diff --git a/src/js/_enqueues/lib/codemirror/javascript-lint.js b/src/js/_enqueues/lib/codemirror/javascript-lint.js
index 2c96798a20ae3..74c4cbacc0c5f 100644
--- a/src/js/_enqueues/lib/codemirror/javascript-lint.js
+++ b/src/js/_enqueues/lib/codemirror/javascript-lint.js
@@ -12,10 +12,10 @@ import CodeMirror from 'codemirror';
  * @see https://codemirror.net/5/doc/manual.html#addon_lint
  *
  * @typedef {Object} CodeMirrorLintError
- * @property {string} message - Error message.
- * @property {'error'} severity - Severity.
- * @property {CodeMirror.Position} from - From position.
- * @property {CodeMirror.Position} to - To position.
+ * @property {string} message Error message.
+ * @property {'error'} severity Severity.
+ * @property {CodeMirror.Position} from From position.
+ * @property {CodeMirror.Position} to To position.
  */
 
 /**
@@ -25,12 +25,12 @@ import CodeMirror from 'codemirror';
  * @see https://www.npmjs.com/package/espree#options
  *
  * @typedef {Object} SupportedJSHintOptions
- * @property {import('espree').Options['ecmaVersion']} [esversion] - "This option is used to specify the ECMAScript version to which the code must adhere."
- * @property {boolean} [es5] - "This option enables syntax first defined in the ECMAScript 5.1 specification. This includes allowing reserved keywords as object properties."
- * @property {boolean} [es3] - "This option tells JSHint that your code needs to adhere to ECMAScript 3 specification. Use this option if you need your program to be executable in older browsers—such as Internet Explorer 6/7/8/9—and other legacy JavaScript environments."
- * @property {boolean} [module] - "This option informs JSHint that the input code describes an ECMAScript 6 module. All module code is interpreted as strict mode code."
- * @property {'implied'} [strict] - "This option requires the code to run in ECMAScript 5's strict mode."
- * @property {string} [espreeModuleUrl] - The URL to the espree script module.
+ * @property {import('espree').Options['ecmaVersion']} [esversion] "This option is used to specify the ECMAScript version to which the code must adhere."
+ * @property {boolean} [es5] "This option enables syntax first defined in the ECMAScript 5.1 specification. This includes allowing reserved keywords as object properties."
+ * @property {boolean} [es3] "This option tells JSHint that your code needs to adhere to ECMAScript 3 specification. Use this option if you need your program to be executable in older browsers—such as Internet Explorer 6/7/8/9—and other legacy JavaScript environments."
+ * @property {boolean} [module] "This option informs JSHint that the input code describes an ECMAScript 6 module. All module code is interpreted as strict mode code."
+ * @property {'implied'} [strict] "This option requires the code to run in ECMAScript 5's strict mode."
+ * @property {string} [espreeModuleUrl] The URL to the espree script module.
  */
 
 /**
@@ -38,9 +38,9 @@ import CodeMirror from 'codemirror';
  *
  * @since 7.0.0
  *
- * @param {string} text - Source.
- * @param {SupportedJSHintOptions} options - Linting options.
- * @returns {Promise<CodeMirrorLintError[]>}
+ * @param {string} text Source.
+ * @param {SupportedJSHintOptions} options Linting options.
+ * @return {Promise<CodeMirrorLintError[]>} Linting errors.
  */
 async function validator( text, options ) {
 	if ( ! options.espreeModuleUrl ) {
@@ -84,14 +84,8 @@ CodeMirror.registerHelper( 'lint', 'javascript', validator );
  *
  * @since 7.0.0
  *
- * @param {SupportedJSHintOptions} options - Linting options for JSHint.
- * @return {{
- *     ecmaVersion?: import('espree').Options['ecmaVersion'],
- *     sourceType?: 'module'|'script',
- *     ecmaFeatures?: {
- *         impliedStrict?: true
- *     }
- * }}
+ * @param {SupportedJSHintOptions} options Linting options for JSHint.
+ * @return {import('espree').Options} Options for Espree.
  */
 function getEspreeOptions( options ) {
 	/** @type {{ impliedStrict?: true }} */
@@ -112,7 +106,7 @@ function getEspreeOptions( options ) {
  *
  * @since 7.0.0
  *
- * @param {SupportedJSHintOptions} options - Options.
+ * @param {SupportedJSHintOptions} options Options.
  * @return {import('espree').Options['ecmaVersion']} ECMAScript version.
  */
 function getEcmaVersion( options ) {
diff --git a/src/js/_enqueues/lib/lists.js b/src/js/_enqueues/lib/lists.js
index d7e888c85b9ab..c81848ff5db5d 100644
--- a/src/js/_enqueues/lib/lists.js
+++ b/src/js/_enqueues/lib/lists.js
@@ -5,7 +5,7 @@
 /* global ajaxurl, wpAjax */
 
 /**
- * @param {jQuery} $ jQuery object.
+ * @param {JQueryStatic} $ The jQuery object.
  */
 ( function( $ ) {
 var functions = {
@@ -22,7 +22,7 @@ var functions = {
 wpList = {
 
 	/**
-	 * @member {object}
+	 * @member {Object}
 	 */
 	settings: {
 
@@ -108,9 +108,9 @@ wpList = {
 		 * Callback that's run before a request is made.
 		 *
 		 * @callback wpList~confirm
-		 * @param {object}      this
+		 * @param {Object}      this
 		 * @param {HTMLElement} list            The list DOM element.
-		 * @param {object}      settings        Settings for the current list.
+		 * @param {Object}      settings        Settings for the current list.
 		 * @param {string}      action          The type of action to perform: 'add', 'delete', or 'dim'.
 		 * @param {string}      backgroundColor Background color of the list's DOM element.
 		 * @return {boolean} Whether to proceed with the action or not.
@@ -123,7 +123,7 @@ wpList = {
 		 * Allows to cancel the request.
 		 *
 		 * @callback wpList~addBefore
-		 * @param {object} settings Settings for the Ajax request.
+		 * @param {Object} settings Settings for the Ajax request.
 		 * @return {object|boolean} Settings for the Ajax request or false to abort.
 		 */
 		addBefore: null,
@@ -133,11 +133,11 @@ wpList = {
 		 *
 		 * @callback wpList~addAfter
 		 * @param {XML}    returnedResponse Raw response returned from the server.
-		 * @param {object} settings         Settings for the Ajax request.
+		 * @param {Object} settings         Settings for the Ajax request.
 		 * @param {jqXHR}  settings.xml     jQuery XMLHttpRequest object.
 		 * @param {string} settings.status  Status of the request: 'success', 'notmodified', 'nocontent', 'error',
 		 *                                  'timeout', 'abort', or 'parsererror'.
-		 * @param {object} settings.parsed  Parsed response object.
+		 * @param {Object} settings.parsed  Parsed response object.
 		 */
 		addAfter: null,
 
@@ -147,7 +147,7 @@ wpList = {
 		 * Allows to cancel the request.
 		 *
 		 * @callback wpList~delBefore
-		 * @param {object}      settings Settings for the Ajax request.
+		 * @param {Object}      settings Settings for the Ajax request.
 		 * @param {HTMLElement} list     The list DOM element.
 		 * @return {object|boolean} Settings for the Ajax request or false to abort.
 		 */
@@ -158,11 +158,11 @@ wpList = {
 		 *
 		 * @callback wpList~delAfter
 		 * @param {XML}    returnedResponse Raw response returned from the server.
-		 * @param {object} settings         Settings for the Ajax request.
+		 * @param {Object} settings         Settings for the Ajax request.
 		 * @param {jqXHR}  settings.xml     jQuery XMLHttpRequest object.
 		 * @param {string} settings.status  Status of the request: 'success', 'notmodified', 'nocontent', 'error',
 		 *                                  'timeout', 'abort', or 'parsererror'.
-		 * @param {object} settings.parsed  Parsed response object.
+		 * @param {Object} settings.parsed  Parsed response object.
 		 */
 		delAfter: null,
 
@@ -172,7 +172,7 @@ wpList = {
 		 * Allows to cancel the request.
 		 *
 		 * @callback wpList~dimBefore
-		 * @param {object} settings Settings for the Ajax request.
+		 * @param {Object} settings Settings for the Ajax request.
 		 * @return {object|boolean} Settings for the Ajax request or false to abort.
 		 */
 		dimBefore: null,
@@ -182,11 +182,11 @@ wpList = {
 		 *
 		 * @callback wpList~dimAfter
 		 * @param {XML}    returnedResponse Raw response returned from the server.
-		 * @param {object} settings         Settings for the Ajax request.
+		 * @param {Object} settings         Settings for the Ajax request.
 		 * @param {jqXHR}  settings.xml     jQuery XMLHttpRequest object.
 		 * @param {string} settings.status  Status of the request: 'success', 'notmodified', 'nocontent', 'error',
 		 *                                  'timeout', 'abort', or 'parsererror'.
-		 * @param {object} settings.parsed  Parsed response object.
+		 * @param {Object} settings.parsed  Parsed response object.
 		 */
 		dimAfter: null
 	},
diff --git a/src/js/_enqueues/lib/nav-menu.js b/src/js/_enqueues/lib/nav-menu.js
index 79917c8447f1a..b3e6b93f0408e 100644
--- a/src/js/_enqueues/lib/nav-menu.js
+++ b/src/js/_enqueues/lib/nav-menu.js
@@ -5,12 +5,14 @@
  * @version 2.0.0
  *
  * @package WordPress
- * @subpackage Administration
  * @output wp-admin/js/nav-menu.js
  */
 
 /* global menus, postboxes, columns, isRtl, ajaxurl, wpNavMenu */
 
+/**
+ * @param {JQueryStatic} $ The jQuery object.
+ */
 (function($) {
 
 	var api;
@@ -178,7 +180,7 @@
 				 *
 				 * @ignore
 				 *
-				 * @param jQuery metabox The metabox jQuery object.
+				 * @param {Function} processMethod The method to use for adding the menu items. Defaults to api.addMenuItemToBottom.
 				 */
 				addSelectedToMenu : function(processMethod) {
 					if ( 0 === $('#menu-to-edit').length ) {
@@ -339,7 +341,7 @@
 								}
 							});
 						});
-						
+
 					});
 				},
 				updateOrderDropdown : function() {
@@ -403,7 +405,7 @@
 
 							}
 						});
-						
+
 					});
 				}
 			});
@@ -560,7 +562,7 @@
 			menu.on( 'change', '.edit-menu-item-parent', function() {
 				api.changeMenuParent( $( this ) );
 			});
-			
+
 			// Update menu item order when value is changed.
 			menu.on( 'change', '.edit-menu-item-order', function() {
 				api.changeMenuOrder( $( this ) );
@@ -569,10 +571,10 @@
 
 		/**
 		 * changeMenuParent( [parentDropdown] )
-		 * 
+		 *
 		 * @since 6.7.0
 		 *
-		 * @param {object} parentDropdown select field
+		 * @param {Object} parentDropdown select field
 		 */
 		changeMenuParent : function( parentDropdown ) {
 			var menuItemNewPosition,
@@ -625,10 +627,10 @@
 
 		/**
 		 * changeMenuOrder( [OrderDropdown] )
-		 * 
+		 *
 		 * @since 6.7.0
 		 *
-		 * @param {object} orderDropdown select field
+		 * @param {Object} orderDropdown select field
 		 */
 		changeMenuOrder : function( orderDropdown ) {
 			var menuItems = $( '#menu-to-edit li' ),
@@ -1159,7 +1161,7 @@
 		 * Handle toggling bulk selection checkboxes for menu items.
 		 *
 		 * @since 5.8.0
-		 */ 
+		 */
 		attachBulkSelectButtonListeners : function() {
 			var that = this;
 
@@ -1178,7 +1180,7 @@
 		 * Enable bulk selection checkboxes for menu items.
 		 *
 		 * @since 5.8.0
-		 */ 
+		 */
 		enableBulkSelection : function() {
 			var checkbox = $( '#menu-to-edit .menu-item-checkbox' );
 
@@ -1195,7 +1197,7 @@
 		 * Disable bulk selection checkboxes for menu items.
 		 *
 		 * @since 5.8.0
-		 */ 
+		 */
 		disableBulkSelection : function() {
 			var checkbox = $( '#menu-to-edit .menu-item-checkbox' );
 
@@ -1219,7 +1221,7 @@
 		 * Listen for state changes on bulk action checkboxes.
 		 *
 		 * @since 5.8.0
-		 */ 
+		 */
 		attachMenuCheckBoxListeners : function() {
 			var that = this;
 
@@ -1232,7 +1234,7 @@
 		 * Create delete button to remove menu items from collection.
 		 *
 		 * @since 5.8.0
-		 */ 
+		 */
 		attachMenuItemDeleteButton : function() {
 			var that = this;
 
@@ -1275,7 +1277,7 @@
 		 * List menu items awaiting deletion.
 		 *
 		 * @since 5.8.0
-		 */ 
+		 */
 		attachPendingMenuItemsListForDeletion : function() {
 			$( '#post-body-content' ).on( 'change', '.menu-item-checkbox', function() {
 				var menuItemName, menuItemType, menuItemID, listedMenuItem;
@@ -1317,7 +1319,7 @@
 		 * Set status of bulk delete checkbox.
 		 *
 		 * @since 5.8.0
-		 */ 
+		 */
 		setBulkDeleteCheckboxStatus : function() {
 			var that = this;
 			var checkbox = $( '#menu-to-edit .menu-item-checkbox' );
@@ -1341,7 +1343,7 @@
 		 * Set status of menu items removal button.
 		 *
 		 * @since 5.8.0
-		 */ 
+		 */
 		setRemoveSelectedButtonStatus : function() {
 			var button = $( '.menu-items-delete' );
 
@@ -1419,7 +1421,7 @@
 			}
 
 			/*
-			 * Reset results when search is less than or equal to 
+			 * Reset results when search is less than or equal to
 			 * minimum characters for searched term.
 			 */
 			if ( q.length <= minSearchLength ) {
@@ -1766,9 +1768,9 @@
 		/**
 		 * Process the quick search response into a search result
 		 *
-		 * @param string resp The server response to the query.
-		 * @param object req The request arguments.
-		 * @param jQuery panel The tabs panel we're searching in.
+		 * @param {string} resp  The server response to the query.
+		 * @param {Object} req   The request arguments.
+		 * @param {jQuery} panel The tabs panel we're searching in.
 		 */
 		processQuickSearchQueryResponse : function(resp, req, panel) {
 			var matched, newID,
diff --git a/src/js/_enqueues/lib/pointer.js b/src/js/_enqueues/lib/pointer.js
index 9d043f6dee141..d946d6c015121 100644
--- a/src/js/_enqueues/lib/pointer.js
+++ b/src/js/_enqueues/lib/pointer.js
@@ -4,6 +4,8 @@
 
 /**
  * Initializes the wp-pointer widget using jQuery UI Widget Factory.
+ *
+ * @param {JQueryStatic} $ The jQuery object.
  */
 (function($){
 	var identifier = 0,
@@ -146,7 +148,7 @@
 		 *
 		 * @param {Object} event The event that caused the update.
 		 *
-		 * @return {Promise} Resolves when the update has been executed.
+		 * @return {Promise|void} Resolves when the update has been executed.
 		 */
 		update: function( event ) {
 			var self = this,
diff --git a/src/js/_enqueues/lib/quicktags.js b/src/js/_enqueues/lib/quicktags.js
index 4b1a80fa28c94..621fab1058315 100644
--- a/src/js/_enqueues/lib/quicktags.js
+++ b/src/js/_enqueues/lib/quicktags.js
@@ -1,4 +1,3 @@
-
 /*
  * Quicktags
  *
@@ -330,16 +329,16 @@ window.edToolbar = function(){};
 	 *     QTags.addButton( 'my_id', 'my button', '<span>', '</span>' );
 	 *     QTags.addButton( 'my_id2', 'my button', '<br />' );
 	 *
-	 * @param string id Required. Button HTML ID
-	 * @param string display Required. Button's value="..."
-	 * @param string|function arg1 Required. Either a starting tag to be inserted like "<span>" or a callback that is executed when the button is clicked.
-	 * @param string arg2 Optional. Ending tag like "</span>"
-	 * @param string access_key Deprecated Not used
-	 * @param string title Optional. Button's title="..."
-	 * @param int priority Optional. Number representing the desired position of the button in the toolbar. 1 - 9 = first, 11 - 19 = second, 21 - 29 = third, etc.
-	 * @param string instance Optional. Limit the button to a specific instance of Quicktags, add to all instances if not present.
-	 * @param attr object Optional. Used to pass additional attributes. Currently supports `ariaLabel` and `ariaLabelClose` (for "close tag" state)
-	 * @return mixed null or the button object that is needed for back-compat.
+	 * @param {string}          id           Required. Button HTML ID
+	 * @param {string}          display      Required. Button's value="..."
+	 * @param {string|Function} arg1         Required. Either a starting tag to be inserted like "<span>" or a callback that is executed when the button is clicked.
+	 * @param {string}          arg2         Optional. Ending tag like "</span>"
+	 * @param {string}          [access_key] Deprecated Not used
+	 * @param {string}          [title]      Optional. Button's title="..."
+	 * @param {number}          [priority]   Optional. Number representing the desired position of the button in the toolbar. 1 - 9 = first, 11 - 19 = second, 21 - 29 = third, etc.
+	 * @param {string}          [instance]   Optional. Limit the button to a specific instance of Quicktags, add to all instances if not present.
+	 * @param {Object}          [attr]       Optional. Used to pass additional attributes. Currently supports `ariaLabel` and `ariaLabelClose` (for "close tag" state)
+	 * @return {void|Object} Returns the button object if priority is -1, otherwise returns void.
 	 */
 	qt.addButton = function( id, display, arg1, arg2, access_key, title, priority, instance, attr ) {
 		var btn;
@@ -723,26 +722,38 @@ window.edToolbar = function(){};
 
 /**
  * Initialize new instance of the Quicktags editor
+ *
+ * @param {Object} settings The settings for the Quicktags editor.
+ * @return {Object} The Quicktags editor instance.
  */
 window.quicktags = function(settings) {
 	return new window.QTags(settings);
 };
 
 /**
- * Inserts content at the caret in the active editor (textarea)
+ * Inserts content at the caret in the active editor (textarea).
  *
  * Added for back compatibility
+ * @param {string} bah The ID of the textarea.
+ * @param {string} txt The content to insert.
  * @see QTags.insertContent()
+ * @return {boolean} True if the content was inserted, false otherwise.
  */
 window.edInsertContent = function(bah, txt) {
 	return window.QTags.insertContent(txt);
 };
 
 /**
- * Adds a button to all instances of the editor
+ * Adds a button to all instances of the editor.
  *
  * Added for back compatibility, use QTags.addButton() as it gives more flexibility like type of button, button placement, etc.
+ * @param {string} id       The ID of the button.
+ * @param {string} display  The display text of the button.
+ * @param {string} tagStart The starting tag.
+ * @param {string} tagEnd   The ending tag.
+ * @param {string} access   The access key for the button.
  * @see QTags.addButton()
+ * @return {void|Object} Returns the button object if priority is -1, otherwise returns void.
  */
 window.edButton = function(id, display, tagStart, tagEnd, access) {
 	return window.QTags.addButton( id, display, tagStart, tagEnd, access, '', -1 );
diff --git a/src/js/_enqueues/wp/api-request.js b/src/js/_enqueues/wp/api-request.js
index 58ef53117903e..3404fc848874c 100644
--- a/src/js/_enqueues/wp/api-request.js
+++ b/src/js/_enqueues/wp/api-request.js
@@ -14,6 +14,9 @@
  * @output wp-includes/js/api-request.js
  */
 
+/**
+ * @param {JQueryStatic} $ The jQuery object.
+ */
 ( function( $ ) {
 	var wpApiSettings = window.wpApiSettings;
 
diff --git a/src/js/_enqueues/wp/api.js b/src/js/_enqueues/wp/api.js
index 9e68d77553c56..8773f4f3acdfe 100644
--- a/src/js/_enqueues/wp/api.js
+++ b/src/js/_enqueues/wp/api.js
@@ -1,4 +1,6 @@
 /**
+ * @param {Window}    window    The global window object.
+ * @param {undefined} undefined The undefined value.
  * @output wp-includes/js/wp-api.js
  */
 
@@ -47,8 +49,7 @@
 	/**
 	 * Determine model based on API route.
 	 *
-	 * @param {string} route    The API route.
-	 *
+	 * @param {string} route The API route.
 	 * @return {Backbone Model} The model found at given route. Undefined if not found.
 	 */
 	wp.api.getModelByRoute = function( route ) {
@@ -60,8 +61,7 @@
 	/**
 	 * Determine collection based on API route.
 	 *
-	 * @param {string} route    The API route.
-	 *
+	 * @param {string} route The API route.
 	 * @return {Backbone Model} The collection found at given route. Undefined if not found.
 	 */
 	wp.api.getCollectionByRoute = function( route ) {
@@ -100,7 +100,9 @@
 	/**
 	 * Parse date into ISO 8601 format.
 	 *
-	 * @param {Date} date.
+	 * @param {Date} date A date object to parse.
+	 *
+	 * @return {number} The timestamp of the date.
 	 */
 	wp.api.utils.parseISO8601 = function( date ) {
 		var timestamp, struct, i, k,
@@ -152,6 +154,9 @@
 
 	/**
 	 * Helper for capitalizing strings.
+	 *
+	 * @param {string} str The string to capitalize.
+	 * @return {string} The capitalized string.
 	 */
 	wp.api.utils.capitalize = function( str ) {
 		if ( _.isUndefined( str ) ) {
@@ -163,6 +168,9 @@
 	/**
 	 * Helper function that capitalizes the first word and camel cases any words starting
 	 * after dashes, removing the dashes.
+	 *
+	 * @param {string} str The string to capitalize and camel case.
+	 * @return {string} The capitalized and camel cased string.
 	 */
 	wp.api.utils.capitalizeAndCamelCaseDashes = function( str ) {
 		if ( _.isUndefined( str ) ) {
@@ -175,6 +183,9 @@
 
 	/**
 	 * Helper function to camel case the letter after dashes, removing the dashes.
+	 *
+	 * @param {string} str The string to camel case.
+	 * @return {string} The camel cased string.
 	 */
 	wp.api.utils.camelCaseDashes = function( str ) {
 		return str.replace( /-([a-z])/g, function( g ) {
@@ -190,6 +201,7 @@
 	 *                                  Example route `/a/b/c`: part 1 is `c`, part 2 is `b`, part 3 is `a`.
 	 * @param {string}  [versionString] Version string, defaults to `wp.api.versionString`.
 	 * @param {boolean} [reverse]       Whether to reverse the order when extracting the route part. Optional, default false.
+	 * @return {string} The route part.
 	 */
 	wp.api.utils.extractRoutePart = function( route, part, versionString, reverse ) {
 		var routeParts;
@@ -216,6 +228,7 @@
 	 * Extract a parent name from a passed route.
 	 *
 	 * @param {string} route The route to extract a name from.
+	 * @return {string} The parent name.
 	 */
 	wp.api.utils.extractParentName = function( route ) {
 		var name,
@@ -291,6 +304,7 @@
 	 * @param {Backbone Model} model          The model to attach helpers and mixins to.
 	 * @param {string}         modelClassName The classname of the constructed model.
 	 * @param {Object} 	       loadingObjects An object containing the models and collections we are building.
+	 * @return {undefined} No return value.
 	 */
 	wp.api.utils.addMixinsAndHelpers = function( model, modelClassName, loadingObjects ) {
 
@@ -320,9 +334,10 @@
 				 * This helper function accepts a field and Date object. It converts the passed Date
 				 * to an ISO string and sets that on the model field.
 				 *
-				 * @param {Date}   date   A JavaScript date object. WordPress expects dates in UTC.
-				 * @param {string} field  The date field to set. One of 'date', 'date_gmt', 'date_modified'
-				 *                        or 'date_modified_gmt'. Optional, defaults to 'date'.
+				 * @param {Date}   date  A JavaScript date object. WordPress expects dates in UTC.
+				 * @param {string} field The date field to set. One of 'date', 'date_gmt', 'date_modified'
+				 *                       or 'date_modified_gmt'. Optional, defaults to 'date'.
+				 * @return {void|boolean} False if the field is not a parseable date field, true otherwise.
 				 */
 				setDate: function( date, field ) {
 					var theField = field || 'date';
@@ -341,8 +356,9 @@
 				 * WordPress returns 'date' and 'date_modified' in the timezone of the server as well as
 				 * UTC dates as 'date_gmt' and 'date_modified_gmt'. Draft posts do not include UTC dates.
 				 *
-				 * @param {string} field  The date field to set. One of 'date', 'date_gmt', 'date_modified'
-				 *                        or 'date_modified_gmt'. Optional, defaults to 'date'.
+				 * @param {string} field The date field to set. One of 'date', 'date_gmt', 'date_modified'
+				 *                       or 'date_modified_gmt'. Optional, defaults to 'date'.
+				 * @return {Date|boolean} A JavaScript Date object, or false if the field is not a parseable date field.
 				 */
 				getDate: function( field ) {
 					var theField   = field || 'date',
@@ -494,6 +510,9 @@
 
 			/**
 			 * Set the model post parent.
+			 *
+			 * @param {wp.api.collections} collection The collection to set the parent post for.
+			 * @param {number}             postId     The ID of the parent post.
 			 */
 			setHelperParentPost = function( collection, postId ) {
 
@@ -590,6 +609,7 @@
 				 * Accepts an array of tag slugs, or a Tags collection.
 				 *
 				 * @param {Array|Backbone.Collection} tags The tags to set on the post.
+				 * @return {void|boolean} False if the tags parameter is a string, otherwise void.
 				 *
 				 */
 				setTags: function( tags ) {
@@ -636,6 +656,7 @@
 				 * Accepts a Tags collection.
 				 *
 				 * @param {Array|Backbone.Collection} tags The tags to set on the post.
+				 * @return {void} No return value.
 				 *
 				 */
 				setTagsWithCollection: function( tags ) {
@@ -674,7 +695,7 @@
 				 * Accepts an array of category slugs, or a Categories collection.
 				 *
 				 * @param {Array|Backbone.Collection} categories The categories to set on the post.
-				 *
+				 * @return {void|boolean} False if the categories parameter is a string, otherwise void.
 				 */
 				setCategories: function( categories ) {
 					var allCategories, newCategory,
@@ -721,7 +742,7 @@
 				 * Accepts Categories collection.
 				 *
 				 * @param {Array|Backbone.Collection} categories The categories to set on the post.
-				 *
+				 * @return {void} No return value.
 				 */
 				setCategoriesWithCollection: function( categories ) {
 
@@ -834,9 +855,9 @@
 			/**
 			 * Set nonce header before every Backbone sync.
 			 *
-			 * @param {string} method.
-			 * @param {Backbone.Model} model.
-			 * @param {{beforeSend}, *} options.
+			 * @param {string}          method  The CRUD method ("create", "read", "update", or "delete") to be performed.
+			 * @param {Backbone.Model}  model   The model to be synced.
+			 * @param {{beforeSend}, *} options Additional options for the sync.
 			 * @return {*}.
 			 */
 			sync: function( method, model, options ) {
@@ -888,6 +909,9 @@
 
 			/**
 			 * Save is only allowed when the PUT OR POST methods are available for the endpoint.
+			 * @param {Object} attrs   The attributes to save.
+			 * @param {Object} options The options for the save operation.
+			 * @return {boolean} True if the save was executed, false if not allowed.
 			 */
 			save: function( attrs, options ) {
 
@@ -905,6 +929,8 @@
 
 			/**
 			 * Delete is only allowed when the DELETE method is available for the endpoint.
+			 * @param {Object} [options] The options for the delete operation.
+			 * @return {boolean} True if the delete was executed, false if not allowed.
 			 */
 			destroy: function( options ) {
 
@@ -967,6 +993,8 @@
 
 			/**
 			 * Setup default state.
+			 * @param {Backbone.Model[]} models    The initial array of models.
+			 * @param {Object}           [options] The options for the collection.
 			 */
 			initialize: function( models, options ) {
 				this.state = {
@@ -987,9 +1015,9 @@
 			 *
 			 * Set nonce header before every Backbone sync.
 			 *
-			 * @param {string} method.
-			 * @param {Backbone.Model} model.
-			 * @param {{success}, *} options.
+			 * @param {string}         method  The CRUD method ("create", "read", "update", or "delete") to be performed.
+			 * @param {Backbone.Model} model   The model to be synced.
+			 * @param {{success}, *}   options Additional options for the sync.
 			 * @return {*}.
 			 */
 			sync: function( method, model, options ) {
@@ -1064,7 +1092,7 @@
 			/**
 			 * Fetches the next page of objects if a new page exists.
 			 *
-			 * @param {data: {page}} options.
+			 * @param {data: {page}} options An object containing the page number to fetch. If not provided, the next page will be fetched.
 			 * @return {*}.
 			 */
 			more: function( options ) {
@@ -1091,7 +1119,7 @@
 			/**
 			 * Returns true if there are more pages of objects available.
 			 *
-			 * @return {null|boolean}
+			 * @return {null|boolean} Returns null if the current page, total pages, or total objects are unknown. Otherwise returns true if there are more pages available.
 			 */
 			hasMore: function() {
 				if ( null === this.state.totalPages ||
@@ -1499,10 +1527,11 @@
 	 * Initialize the wp-api, optionally passing the API root.
 	 *
 	 * @param {Object} [args]
-	 * @param {string} [args.nonce] The nonce. Optional, defaults to wpApiSettings.nonce.
-	 * @param {string} [args.apiRoot] The api root. Optional, defaults to wpApiSettings.root.
+	 * @param {string} [args.nonce]         The nonce. Optional, defaults to wpApiSettings.nonce.
+	 * @param {string} [args.apiRoot]       The api root. Optional, defaults to wpApiSettings.root.
 	 * @param {string} [args.versionString] The version string. Optional, defaults to wpApiSettings.root.
-	 * @param {Object} [args.schema] The schema. Optional, will be fetched from API if not provided.
+	 * @param {Object} [args.schema]        The schema. Optional, will be fetched from API if not provided.
+	 * @return {Promise} A promise that resolves with the endpoint once it is ready.
 	 */
 	wp.api.init = function( args ) {
 		var endpoint, attributes = {}, deferred, promise;
diff --git a/src/js/_enqueues/wp/autosave.js b/src/js/_enqueues/wp/autosave.js
index 9f46c3161483e..35d7a055ed98e 100644
--- a/src/js/_enqueues/wp/autosave.js
+++ b/src/js/_enqueues/wp/autosave.js
@@ -13,8 +13,8 @@ window.autosave = function() {
  *
  * @since 3.9.0
  *
- * @param {jQuery} $ jQuery object.
- * @param {window} The window object.
+ * @param {JQueryStatic} $      The jQuery object.
+ * @param {Object}       window The window object.
  *
  */
 ( function( $, window ) {
@@ -243,6 +243,7 @@ window.autosave = function() {
 			 * Sets the storage for this blog. Confirms that the data was saved
 			 * successfully.
 			 *
+			 * @param {Object} stored_obj The storage object to set.
 			 * @since 3.9.0
 			 *
 			 * @return {boolean} True if the data was saved successfully, false if it wasn't saved.
diff --git a/src/js/_enqueues/wp/code-editor.js b/src/js/_enqueues/wp/code-editor.js
index ed8be9d6a5580..74276d6438011 100644
--- a/src/js/_enqueues/wp/code-editor.js
+++ b/src/js/_enqueues/wp/code-editor.js
@@ -4,8 +4,6 @@
 
 /* global console */
 
-/* eslint-env es2020 */
-
 if ( 'undefined' === typeof window.wp ) {
 	/**
 	 * @namespace wp
@@ -20,7 +18,7 @@ if ( 'undefined' === typeof window.wp.codeEditor ) {
 }
 
 /**
- * @typedef {object} CodeMirrorState
+ * @typedef {Object} CodeMirrorState
  * @property {boolean} [completionActive] - Whether completion is active.
  * @property {boolean} [focused] - Whether the editor is focused.
  */
@@ -35,7 +33,7 @@ if ( 'undefined' === typeof window.wp.codeEditor ) {
  */
 
 /**
- * @typedef {object} LintAnnotation
+ * @typedef {Object} LintAnnotation
  * @property {string} message - Message.
  * @property {'error'|'warning'} severity - Severity.
  * @property {import('codemirror').Position} from - From position.
@@ -43,8 +41,8 @@ if ( 'undefined' === typeof window.wp.codeEditor ) {
  */
 
 /**
- * @typedef {object} CodeMirrorTokenState
- * @property {object} [htmlState] - HTML state.
+ * @typedef {Object} CodeMirrorTokenState
+ * @property {Object} [htmlState] - HTML state.
  * @property {string} [htmlState.tagName] - Tag name.
  * @property {CodeMirrorTokenState} [curState] - Current state.
  */
@@ -60,7 +58,7 @@ if ( 'undefined' === typeof window.wp.codeEditor ) {
  */
 
 /**
- * @typedef {object} CSSLintRules
+ * @typedef {Object} CSSLintRules
  * @property {boolean} [errors] - Errors.
  * @property {boolean} [box-model] - Box model rules.
  * @property {boolean} [display-property-grouping] - Display property grouping rules.
@@ -70,7 +68,7 @@ if ( 'undefined' === typeof window.wp.codeEditor ) {
  */
 
 /**
- * @typedef {object} JSHintRules
+ * @typedef {Object} JSHintRules
  * @property {number} [esversion] - ECMAScript version.
  * @property {boolean} [module] - Whether to use modules.
  * @property {boolean} [boss] - Whether to allow assignments in control expressions.
@@ -89,7 +87,7 @@ if ( 'undefined' === typeof window.wp.codeEditor ) {
  */
 
 /**
- * @typedef {object} HTMLHintRules
+ * @typedef {Object} HTMLHintRules
  * @property {boolean} [tagname-lowercase] - Tag name lowercase rules.
  * @property {boolean} [attr-lowercase] - Attribute lowercase rules.
  * @property {boolean} [attr-value-double-quotes] - Attribute value double quotes rules.
@@ -109,7 +107,7 @@ if ( 'undefined' === typeof window.wp.codeEditor ) {
 /**
  * Settings for the code editor.
  *
- * @typedef {object} CodeEditorSettings
+ * @typedef {Object} CodeEditorSettings
  *
  * @property {CodeMirrorSettings} [codemirror] - CodeMirror settings.
  * @property {CSSLintRules} [csslint] - CSSLint rules.
@@ -127,20 +125,20 @@ if ( 'undefined' === typeof window.wp.codeEditor ) {
  */
 
 /**
- * @typedef {object} CodeEditorInstance
+ * @typedef {Object} CodeEditorInstance
  * @property {CodeEditorSettings} settings - The code editor settings.
  * @property {CodeMirrorEditor} codemirror - The CodeMirror instance.
  * @property {() => void} updateErrorNotice - Force update the error notice.
  */
 
 /**
- * @typedef {object} WpCodeEditor
+ * @typedef {Object} WpCodeEditor
  * @property {CodeEditorSettings} defaultSettings - Default settings.
  * @property {(textarea: string|JQuery|Element, settings?: CodeEditorSettings) => CodeEditorInstance} initialize - Initialize.
  */
 
 /**
- * @param {JQueryStatic} $ - jQuery.
+ * @param {JQueryStatic} $ The jQuery object.
  * @param {Object & {
  *   codeEditor: WpCodeEditor,
  *   CodeMirror: typeof import('codemirror'),
@@ -173,7 +171,7 @@ if ( 'undefined' === typeof window.wp.codeEditor ) {
 	 *
 	 * @return {LintingController} Linting controller.
 	 */
-	function configureLinting( settings ) { // eslint-disable-line complexity
+	function configureLinting( settings ) {
 		/** @type {LintAnnotation[]} */
 		let currentErrorAnnotations = [];
 
@@ -198,7 +196,7 @@ if ( 'undefined' === typeof window.wp.codeEditor ) {
 		 *
 		 * @return {CombinedLintOptions|false} Lint options.
 		 */
-		function getLintOptions() { // eslint-disable-line complexity
+		function getLintOptions() {
 			/** @type {CombinedLintOptions | boolean} */
 			let options = settings.codemirror?.lint ?? false;
 
@@ -397,7 +395,7 @@ if ( 'undefined' === typeof window.wp.codeEditor ) {
 	}
 
 	/**
-	 * @typedef {object} LintingController
+	 * @typedef {Object} LintingController
 	 * @property {() => CombinedLintOptions|false} getLintOptions - Get lint options.
 	 * @property {(editor: CodeMirrorEditor) => void} init - Initialize.
 	 * @property {(editor: import('codemirror').Editor) => void} updateErrorNotice - Update error notice.
diff --git a/src/js/_enqueues/wp/custom-header.js b/src/js/_enqueues/wp/custom-header.js
index ae43f56174f23..1771ce7505544 100644
--- a/src/js/_enqueues/wp/custom-header.js
+++ b/src/js/_enqueues/wp/custom-header.js
@@ -76,7 +76,7 @@
 		 *
 		 * Themes and plugins can override this method to change the criteria.
 		 *
-		 * @return {boolean}
+		 * @return {boolean} True if the environment supports video, false otherwise.
 		 */
 		supportsVideo: function() {
 			// Don't load video on small screens. @todo Consider bandwidth and other factors.
@@ -163,7 +163,7 @@
 		 * Whether the video is paused.
 		 *
 		 * @abstract
-		 * @return {boolean}
+		 * @return {boolean} True if the video is paused, false otherwise.
 		 */
 		isPaused: function() {},
 
@@ -217,8 +217,7 @@
 		 * Whether the handler can process a video.
 		 *
 		 * @abstract
-		 * @param {Object} settings Video settings.
-		 * @return {boolean}
+		 * @return {boolean} True if the handler can process a video, false otherwise. Default is false.
 		 */
 		test: function() {
 			return false;
@@ -240,7 +239,7 @@
 	 * @memberOf wp
 	 *
 	 * @param {Object} protoProps Properties to apply to the prototype.
-	 * @return CustomHandler The subclass.
+	 * @return {Function} Custom handler constructor.
 	 */
 	BaseHandler.extend = function( protoProps ) {
 		var prop;
@@ -272,7 +271,7 @@
 		 * Whether the native handler supports a video.
 		 *
 		 * @param {Object} settings Video settings.
-		 * @return {boolean}
+		 * @return {boolean} True if the native handler supports a video, false otherwise.
 		 */
 		test: function( settings ) {
 			var video = document.createElement( 'video' );
@@ -314,7 +313,7 @@
 		/**
 		 * Whether the video is paused.
 		 *
-		 * @return {boolean}
+		 * @return {boolean} True if the video is paused, false otherwise.
 		 */
 		isPaused: function() {
 			return this.video.paused;
@@ -347,7 +346,7 @@
 		 * Whether the handler supports a video.
 		 *
 		 * @param {Object} settings Video settings.
-		 * @return {boolean}
+		 * @return {boolean} True if the handler supports a video, false otherwise.
 		 */
 		test: function( settings ) {
 			return 'video/x-youtube' === settings.mimeType;
@@ -423,7 +422,7 @@
 		/**
 		 * Whether the video is paused.
 		 *
-		 * @return {boolean}
+		 * @return {boolean} True if the video is paused, false otherwise.
 		 */
 		isPaused: function() {
 			return YT.PlayerState.PAUSED === this.player.getPlayerState();
diff --git a/src/js/_enqueues/wp/dashboard.js b/src/js/_enqueues/wp/dashboard.js
index 0c92f1e1b3e47..31c9cd7cb1547 100644
--- a/src/js/_enqueues/wp/dashboard.js
+++ b/src/js/_enqueues/wp/dashboard.js
@@ -633,10 +633,10 @@ jQuery( function( $ ) {
 		 *
 		 * @since 5.5.2
 		 *
-		 * @param {Array}  rawEvents  The events that should have dynamic fields added to them.
-		 * @param {string} timeFormat A time format acceptable by `wp.date.dateI18n()`.
+		 * @param {Object[]} rawEvents  The events that should have dynamic fields added to them.
+		 * @param {string}   timeFormat A time format acceptable by `wp.date.dateI18n()`.
 		 *
-		 * @returns {Array}
+		 * @return {Object[]} The events with dynamic fields added to them.
 		 */
 		populateDynamicEventFields: function( rawEvents, timeFormat ) {
 			// Clone the parameter to avoid mutating it, so that this can remain a pure function.
@@ -668,9 +668,9 @@ jQuery( function( $ ) {
 		 *
 		 * @since 5.5.2
 		 *
-		 * @param startTimestamp
+		 * @param {number} startTimestamp The start timestamp of the event.
 		 *
-		 * @returns {string|number}
+		 * @return {string|number} A time zone string like `America/Chicago`, or a number representing the offset from UTC in minutes.
 		 */
 		getTimeZone: function( startTimestamp ) {
 			/*
@@ -705,7 +705,7 @@ jQuery( function( $ ) {
 		 *
 		 * @param {number} startTimestamp
 		 *
-		 * @returns {number}
+		 * @return {number} The offset from UTC in minutes, with the sign flipped to be more intuitive.
 		 */
 		getFlippedTimeZoneOffset: function( startTimestamp ) {
 			return new Date( startTimestamp ).getTimezoneOffset() * -1;
@@ -718,7 +718,7 @@ jQuery( function( $ ) {
 		 *
 		 * @param {number} startTimestamp
 		 *
-		 * @returns {string}
+		 * @return {string} A short time zone name, like `PST`, or a string like `GMT+5` if the abbreviation can't be determined.
 		 */
 		getTimeZoneAbbreviation: function( startTimestamp ) {
 			var timeZoneAbbreviation,
@@ -758,11 +758,11 @@ jQuery( function( $ ) {
 		 *
 		 * @since 5.5.2
 		 *
-		 * @param {int}    startDate   The Unix timestamp in milliseconds when the event starts.
-		 * @param {int}    endDate     The Unix timestamp in milliseconds when the event ends.
-		 * @param {string} timeZone    A time zone string or offset which is parsable by `wp.date.i18n()`.
+		 * @param {number} startDate The Unix timestamp in milliseconds when the event starts.
+		 * @param {number} endDate   The Unix timestamp in milliseconds when the event ends.
+		 * @param {string} timeZone  A time zone string or offset which is parsable by `wp.date.i18n()`.
 		 *
-		 * @returns {string}
+		 * @return {string} A formatted date string, like `Mon, Jan 1, 2024` or `Jan 1–3, 2024`.
 		 */
 		getFormattedDate: function( startDate, endDate, timeZone ) {
 			var formattedDate;
@@ -834,7 +834,7 @@ jQuery( function( $ ) {
  * @since 4.8.0
  * @deprecated 5.6.0
  *
- * @type {object}
+ * @type {Object}
 */
 window.communityEventsData.l10n = window.communityEventsData.l10n || {
 	enter_closest_city: '',
diff --git a/src/js/_enqueues/wp/editor/base.js b/src/js/_enqueues/wp/editor/base.js
index b5f1731d4afc5..c2c264e3f8045 100644
--- a/src/js/_enqueues/wp/editor/base.js
+++ b/src/js/_enqueues/wp/editor/base.js
@@ -11,6 +11,7 @@ window.wp = window.wp || {};
 	 * Utility functions for the editor.
 	 *
 	 * @since 2.5.0
+	 * @return {Object} The editor utility functions.
 	 */
 	function SwitchEditors() {
 		var tinymce, $$,
@@ -239,8 +240,8 @@ window.wp = window.wp || {};
 		 * @param {string} content The text content to check against.
 		 * @param {number} cursorPosition    The cursor position to check.
 		 *
-		 * @return {(undefined|Object)} Undefined if the cursor is not wrapped in a shortcode tag.
-		 *                              Information about the wrapping shortcode tag if it's wrapped in one.
+		 * @return {void|Object} Undefined if the cursor is not wrapped in a shortcode tag.
+		 *                       Information about the wrapping shortcode tag if it's wrapped in one.
 		 */
 		function getShortcodeWrapperInfo( content, cursorPosition ) {
 			var contentShortcodes = getShortCodePositionsInText( content );
@@ -258,6 +259,7 @@ window.wp = window.wp || {};
 		 * Gets a list of unique shortcodes or shortcode-lookalikes in the content.
 		 *
 		 * @param {string} content The content we want to scan for shortcodes.
+		 * @return {string[]} An array of unique shortcodes found in the content.
 		 */
 		function getShortcodesInText( content ) {
 			var shortcodes = content.match( /\[+([\w_-])+/g ),
@@ -290,7 +292,8 @@ window.wp = window.wp || {};
 		 * The information can also be used in other cases when we need to lookup shortcode data,
 		 * as it's already structured!
 		 *
-		 * @param {string} content The content we want to scan for shortcodes
+		 * @param {string} content The content we want to scan for shortcodes.
+		 * @return {Object[]} An array of objects with information about the shortcodes found in the content.
 		 */
 		function getShortCodePositionsInText( content ) {
 			var allShortcodes = getShortcodesInText( content ), shortcodeInfo;
@@ -362,6 +365,7 @@ window.wp = window.wp || {};
 		 *
 		 * @param {Object} domLib DOM library instance.
 		 * @param {string} content The content to insert into the cursor marker element.
+		 * @return {Object} The cursor marker element.
 		 */
 		function getCursorMarkerSpan( domLib, content ) {
 			return domLib( '<span>' ).css( {
@@ -385,7 +389,7 @@ window.wp = window.wp || {};
 		 * @param {string} content Textarea content that the cursors are in
 		 * @param {{cursorStart: number, cursorEnd: number}} cursorPositions Cursor start and end positions
 		 *
-		 * @return {{cursorStart: number, cursorEnd: number}}
+		 * @return {{cursorStart: number, cursorEnd: number}} Adjusted cursor positions with `cursorStart` and `cursorEnd` properties.
 		 */
 		function adjustTextAreaSelectionCursors( content, cursorPositions ) {
 			var voidElements = [
@@ -649,7 +653,7 @@ window.wp = window.wp || {};
 		 * and why this solution was chosen.
 		 *
 		 * @param {Object} editor The editor where we must find the selection.
-		 * @return {(null|Object)} The selection range position in the editor.
+		 * @return {void|Object} The selection range position in the editor.
 		 */
 		function findBookmarkedPosition( editor ) {
 			// Get the TinyMCE `window` reference, since we need to access the raw selection.
@@ -1381,7 +1385,7 @@ window.wp = window.wp || {};
 	 * @since 4.8.0
 	 *
 	 * @param {string} id The HTML id of the editor textarea.
-	 * @return The editor content.
+	 * @return {void|string} The editor content.
 	 */
 	wp.editor.getContent = function( id ) {
 		var editor;
diff --git a/src/js/_enqueues/wp/editor/dfw.js b/src/js/_enqueues/wp/editor/dfw.js
index 04b001e1c8059..37105aecd8bc9 100644
--- a/src/js/_enqueues/wp/editor/dfw.js
+++ b/src/js/_enqueues/wp/editor/dfw.js
@@ -2,6 +2,11 @@
  * @output wp-admin/js/editor-expand.js
  */
 
+/**
+ * @param {Window}       window    The global window object.
+ * @param {JQueryStatic} $         The jQuery object.
+ * @param {undefined}    undefined The undefined value.
+ */
 ( function( window, $, undefined ) {
 	'use strict';
 
@@ -167,7 +172,7 @@
 		 * @since 4.0.0
 		 *
 		 * @param {event} event The TinyMCE editor init event.
-		 * @param {object} editor The editor to bind the vents on.
+		 * @param {Object} editor The editor to bind the vents on.
 		 *
 		 * @return {void}
 		 */
@@ -785,7 +790,7 @@
 		 *
 		 * @since 4.0.0
 		 *
-		 * @param {function} callback The function to run in the timeout.
+		 * @param {Function} callback The function to run in the timeout.
 		 *
 		 * @return {void}
 		 */
@@ -1160,7 +1165,7 @@
 		 *
 		 * @since 4.1.0
 		 *
-		 * @param event The event that triggers this function.
+		 * @param {Event} event The event that triggers this function.
 		 *
 		 * @return {void}
 		 */
@@ -1299,7 +1304,7 @@
 		 *
 		 * @since 4.1.0
 		 *
-		 * @param event The event that triggers this function.
+		 * @param {Event} event The event that triggers this function.
 		 *
 		 * @return {void}
 		 */
@@ -1461,7 +1466,7 @@
 		 * @since 4.1.0
 		 *
 		 * @param {event} event The TinyMCE editor setup event.
-		 * @param {object} editor The editor to add the button to.
+		 * @param {Object} editor The editor to add the button to.
 		 *
 		 * @return {void}
 		 */
@@ -1510,7 +1515,7 @@
 		 * @since 4.1.0
 		 *
 		 * @param {event} event The TinyMCE editor init event.
-		 * @param {object} editor The editor to bind events on.
+		 * @param {Object} editor The editor to bind events on.
 		 *
 		 * @return {void}
 		 */
@@ -1567,7 +1572,7 @@
 		 * @since 4.1.0
 		 *
 		 * @param {event} event The quicktags init event.
-		 * @param {object} editor The editor to bind events on.
+		 * @param {Object} editor The editor to bind events on.
 		 *
 		 * @return {void}
 		 */
diff --git a/src/js/_enqueues/wp/embed.js b/src/js/_enqueues/wp/embed.js
index 315e573f5cb82..724daa3283e93 100644
--- a/src/js/_enqueues/wp/embed.js
+++ b/src/js/_enqueues/wp/embed.js
@@ -1,6 +1,8 @@
 /**
  * WordPress inline HTML embed
  *
+ * @param {Window} window The global window object.
+ * @param {Document} document The global document object.
  * @since 4.4.0
  * @output wp-includes/js/wp-embed.js
  *
@@ -28,7 +30,7 @@
 	/**
 	 * Receive embed message.
 	 *
-	 * @param {MessageEvent} e
+	 * @param {MessageEvent} e The message event.
 	 */
 	window.wp.receiveEmbedMessage = function( e ) {
 		var data = e.data;
@@ -90,7 +92,7 @@
 			i, source, secret;
 
 		for ( i = 0; i < iframes.length; i++ ) {
-			/** @var {IframeElement} */
+			/** @type {HTMLIFrameElement}} */
 			source = iframes[ i ];
 
 			secret = source.getAttribute( 'data-secret' );
diff --git a/src/js/_enqueues/wp/emoji.js b/src/js/_enqueues/wp/emoji.js
index 05582de672662..1c134e2dfef85 100644
--- a/src/js/_enqueues/wp/emoji.js
+++ b/src/js/_enqueues/wp/emoji.js
@@ -2,6 +2,8 @@
  * wp-emoji.js is used to replace emoji with images in browsers when the browser
  * doesn't support emoji natively.
  *
+ * @param {Window} window The global window object.
+ * @param {Object} settings The settings object.
  * @output wp-includes/js/wp-emoji.js
  */
 
diff --git a/src/js/_enqueues/wp/heartbeat.js b/src/js/_enqueues/wp/heartbeat.js
index 65635177d9f66..670d8d047a2ff 100644
--- a/src/js/_enqueues/wp/heartbeat.js
+++ b/src/js/_enqueues/wp/heartbeat.js
@@ -27,6 +27,11 @@
  * @output wp-includes/js/heartbeat.js
  */
 
+/**
+ * @param {JQueryStatic} $         The jQuery object.
+ * @param {Window}       window    The global window object.
+ * @param {undefined}    undefined The undefined value.
+ */
 ( function( $, window, undefined ) {
 
 	/**
@@ -35,7 +40,7 @@
 	 * @since 3.6.0
 	 *
 	 * @return {Object} An instance of the Heartbeat class.
-	 * @constructor
+	 * @class
 	 */
 	var Heartbeat = function() {
 		var $document = $(document),
@@ -281,6 +286,7 @@
 		 * @since 3.6.0
 		 * @access private
 		 *
+		 * @param {HTMLIFrameElement} frame The iframe element to check.
 		 * @return {boolean} Returns whether or not the iframe is from the same origin.
 		 */
 		function isLocalFrame( frame ) {
@@ -824,7 +830,7 @@
 		 *
 		 * @param {string} handle The handle for the data.
 		 *
-		 * @return {boolean} True if the data is queued with this handle.
+		 * @return {void|boolean} True if the data is queued with this handle.
 		 */
 		function isQueued( handle ) {
 			if ( handle ) {
diff --git a/src/js/_enqueues/wp/mce-view.js b/src/js/_enqueues/wp/mce-view.js
index 863803f614816..01dbaedf1f122 100644
--- a/src/js/_enqueues/wp/mce-view.js
+++ b/src/js/_enqueues/wp/mce-view.js
@@ -88,8 +88,8 @@
 		 * replacing any matches with markers,
 		 * and creates a new instance for every match.
 		 *
-		 * @param {string} content The string to scan.
-		 * @param {tinymce.Editor} editor The editor.
+		 * @param {string}         content The string to scan.
+		 * @param {tinymce.Editor} editor  The editor.
 		 *
 		 * @return {string} The string with markers.
 		 */
@@ -190,7 +190,7 @@
 		/**
 		 * Get a view instance.
 		 *
-		 * @param {(string|HTMLElement)} object The textual representation of the view or the view node.
+		 * @param {string|HTMLElement} object The textual representation of the view or the view node.
 		 *
 		 * @return {wp.mce.View} The view instance or undefined.
 		 */
@@ -296,7 +296,7 @@
 		/**
 		 * Whether or not to display a loader.
 		 *
-		 * @type {Boolean}
+		 * @type {boolean}
 		 */
 		loader: true,
 
@@ -308,7 +308,7 @@
 		/**
 		 * Returns the content to render in the view node.
 		 *
-		 * @return {*}
+		 * @return {*} The content.
 		 */
 		getContent: function() {
 			return this.content;
@@ -675,6 +675,8 @@
 
 		/**
 		 * Sets a loader for all view nodes tied to this view instance.
+		 *
+		 * @param {string} dashicon The dashicon ID. Optional.
 		 */
 		setLoader: function( dashicon ) {
 			this.setContent(
@@ -705,7 +707,7 @@
 		 *
 		 * @param {string} content The string to scan.
 		 *
-		 * @return {Object}
+		 * @return {void|Object} An object with the match index, content and options, or undefined if no match was found.
 		 */
 		match: function( content ) {
 			var match = shortcode.next( this.type, content );
diff --git a/src/js/_enqueues/wp/media/audiovideo.js b/src/js/_enqueues/wp/media/audiovideo.js
index f0127cc507119..485a1699726bf 100644
--- a/src/js/_enqueues/wp/media/audiovideo.js
+++ b/src/js/_enqueues/wp/media/audiovideo.js
@@ -44,6 +44,7 @@ wp.media.mixin = {
 	 *
 	 * @since 4.2.0
 	 *
+	 * @param {Object} t The MediaElement player object.
 	 * @return {void}
 	 */
 	removePlayer: function(t) {
diff --git a/src/js/_enqueues/wp/media/editor.js b/src/js/_enqueues/wp/media/editor.js
index 1097bca966fdb..2cb6277f7533b 100644
--- a/src/js/_enqueues/wp/media/editor.js
+++ b/src/js/_enqueues/wp/media/editor.js
@@ -206,7 +206,7 @@
 		 *
 		 * @param {Object} props Attachment details (align, link, size, etc).
 		 * @param {Object} attachment The attachment object, media version of Post.
-		 * @return {string}
+		 * @return {string} The image markup.
 		 */
 		image: function( props, attachment ) {
 			var img = {},
@@ -415,7 +415,7 @@
 			 *      the media items belonging to a collection.
 			 *      The query[ this.tag ] property is a Backbone.Model
 			 *          containing the 'props' for the collection.
-			 * @return {wp.shortcode}
+			 * @return {wp.shortcode} A wp.shortcode instance representing the collection.
 			 */
 			shortcode: function( attachments ) {
 				var props = attachments.props.toJSON(),
@@ -486,7 +486,7 @@
 			 *
 			 * @this wp.media.{prop}
 			 *
-			 * @return {wp.media.view.MediaFrame.Select} A media workflow.
+			 * @return {void|wp.media.view.MediaFrame.Select} A media workflow.
 			 */
 			edit: function( content ) {
 				var shortcode = wp.shortcode.next( this.tag, content ),
@@ -606,7 +606,7 @@
 		/**
 		 * Get the featured image post ID
 		 *
-		 * @return {wp.media.view.settings.post.featuredImageId|number}
+		 * @return {wp.media.view.settings.post.featuredImageId|number} The post ID of the featured image, or -1 if none is set.
 		 */
 		get: function() {
 			return wp.media.view.settings.post.featuredImageId;
@@ -727,7 +727,8 @@
 		/**
 		 * Send content to the editor
 		 *
-		 * @param {string} html Content to send to the editor
+		 * @param {string} html Content to send to the editor.
+		 * @return {void}
 		 */
 		insert: function( html ) {
 			var editor, wpActiveEditor,
@@ -889,7 +890,7 @@
 		 *
 		 * @param {string} [id=''] A slug used to identify the workflow.
 		 *
-		 * @return {wpActiveEditor|string|tinymce.activeEditor.id}
+		 * @return {wpActiveEditor|string|tinymce.activeEditor.id} The current workflow id.
 		 */
 		id: function( id ) {
 			if ( id ) {
@@ -940,7 +941,7 @@
 			 *
 			 * @param {Object} props Attachment details (align, link, size, etc).
 			 * @param {Object} attachment The attachment object, media version of Post.
-			 * @return {Promise}
+			 * @return {Promise} A promise that resolves when the attachment has been sent to the editor.
 			 */
 			attachment: function( props, attachment ) {
 				var caption = attachment.caption,
@@ -995,7 +996,7 @@
 			 * Called when 'Insert From URL' source is not an image. Example: YouTube url.
 			 *
 			 * @param {Object} embed
-			 * @return {Promise}
+			 * @return {Promise} A promise that resolves when the link has been sent to the editor.
 			 */
 			link: function( embed ) {
 				return wp.media.post( 'send-link-to-editor', {
@@ -1008,14 +1009,14 @@
 			}
 		},
 		/**
-		 * Open a workflow
+		 * Opens a workflow.
 		 *
 		 * @param {string} [id=undefined] Optional. A slug used to identify the workflow.
 		 * @param {Object} [options={}]
 		 *
 		 * @this wp.media.editor
 		 *
-		 * @return {wp.media.view.MediaFrame}
+		 * @return {wp.media.view.MediaFrame} A media workflow.
 		 */
 		open: function( id, options ) {
 			var workflow;
diff --git a/src/js/_enqueues/wp/revisions.js b/src/js/_enqueues/wp/revisions.js
index b0c555e934361..3efb3dcb7ac5d 100644
--- a/src/js/_enqueues/wp/revisions.js
+++ b/src/js/_enqueues/wp/revisions.js
@@ -368,8 +368,8 @@ window.wp = window.wp || {};
 	 *
 	 * @see wp.revisions.view.Frame
 	 *
-	 * @param {object}                    attributes        Model attributes - none are required.
-	 * @param {object}                    options           Options for the model.
+	 * @param {Object}                    attributes        Model attributes - none are required.
+	 * @param {Object}                    options           Options for the model.
 	 * @param {revisions.model.Revisions} options.revisions A collection of revisions.
 	 */
 	revisions.model.FrameState = Backbone.Model.extend({
@@ -533,7 +533,7 @@ window.wp = window.wp || {};
 	 *
 	 * Top level frame that orchestrates the revisions experience.
 	 *
-	 * @param {object}                     options       The options hash for the view.
+	 * @param {Object}                     options       The options hash for the view.
 	 * @param {revisions.model.FrameState} options.model The frame state model.
 	 */
 	revisions.view.Frame = wp.Backbone.View.extend({
diff --git a/src/js/_enqueues/wp/sanitize.js b/src/js/_enqueues/wp/sanitize.js
index c0b6b0bed9494..d67bc0b77ad45 100644
--- a/src/js/_enqueues/wp/sanitize.js
+++ b/src/js/_enqueues/wp/sanitize.js
@@ -2,8 +2,6 @@
  * @output wp-includes/js/wp-sanitize.js
  */
 
-/* eslint-env es6 */
-
 ( function () {
 
 	window.wp = window.wp || {};
diff --git a/src/js/_enqueues/wp/theme-plugin-editor.js b/src/js/_enqueues/wp/theme-plugin-editor.js
index 7bcff376e9ff2..88c985be42012 100644
--- a/src/js/_enqueues/wp/theme-plugin-editor.js
+++ b/src/js/_enqueues/wp/theme-plugin-editor.js
@@ -2,14 +2,15 @@
  * @output wp-admin/js/theme-plugin-editor.js
  */
 
-/* eslint-env es2020 */
-
 /* eslint no-magic-numbers: ["error", { "ignore": [-1, 0, 1, 9, 1000] }] */
 
 if ( ! window.wp ) {
 	window.wp = {};
 }
 
+/**
+ * @param {JQueryStatic} $ The jQuery object.
+ */
 wp.themePluginEditor = (function( $ ) {
 	'use strict';
 	var component, TreeLinks,
@@ -476,10 +477,6 @@ wp.themePluginEditor = (function( $ ) {
 		} );
 	};
 
-	/* jshint ignore:start */
-	/* jscs:disable */
-	/* eslint-disable */
-
 	/**
 	 * Creates a new TreeitemLink.
 	 *
@@ -503,9 +500,9 @@ wp.themePluginEditor = (function( $ ) {
 		 */
 
 		/**
-		 *   @constructor
+		 *   @class
 		 *
-		 *   @desc
+		 *   @description
 		 *       Treeitem object for representing the state and user interactions for a
 		 *       treeItem widget
 		 *
@@ -601,10 +598,8 @@ wp.themePluginEditor = (function( $ ) {
 		/* EVENT HANDLERS */
 
 		TreeitemLink.prototype.handleKeydown = function (event) {
-			var tgt = event.currentTarget,
-				flag = false,
-				_char = event.key,
-				clickEvent;
+			var flag = false,
+				_char = event.key;
 
 			function isPrintableCharacter(str) {
 				return str.length === 1 && str.match(/\S/);
@@ -736,7 +731,7 @@ wp.themePluginEditor = (function( $ ) {
 			}
 		};
 
-		TreeitemLink.prototype.handleFocus = function (event) {
+		TreeitemLink.prototype.handleFocus = function () {
 			var node = this.domNode;
 			if (this.isExpandable) {
 				node = node.firstElementChild;
@@ -744,7 +739,7 @@ wp.themePluginEditor = (function( $ ) {
 			node.classList.add('focus');
 		};
 
-		TreeitemLink.prototype.handleBlur = function (event) {
+		TreeitemLink.prototype.handleBlur = function () {
 			var node = this.domNode;
 			if (this.isExpandable) {
 				node = node.firstElementChild;
@@ -1022,10 +1017,6 @@ wp.themePluginEditor = (function( $ ) {
 		return TreeLinks;
 	})();
 
-	/* jshint ignore:end */
-	/* jscs:enable */
-	/* eslint-enable */
-
 	return component;
 })( jQuery );
 
@@ -1035,7 +1026,7 @@ wp.themePluginEditor = (function( $ ) {
  * @since 4.9.0
  * @deprecated 5.5.0
  *
- * @type {object}
+ * @type {Object}
  */
 wp.themePluginEditor.l10n = wp.themePluginEditor.l10n || {
 	saveAlert: '',
diff --git a/src/js/_enqueues/wp/theme.js b/src/js/_enqueues/wp/theme.js
index cfcea1fcc58b7..2249495ea4d1b 100644
--- a/src/js/_enqueues/wp/theme.js
+++ b/src/js/_enqueues/wp/theme.js
@@ -208,7 +208,7 @@ themes.Collection = Backbone.Collection.extend({
 	/**
 	 * Performs a search within the collection.
 	 *
-	 * @uses RegExp
+	 * @param {string} term The search term.
 	 */
 	search: function( term ) {
 		var match, results, haystack, name, description, author;
@@ -1969,7 +1969,7 @@ themes.view.Installer = themes.view.Appearance.extend({
 	/**
 	 * Clears all the checked filters.
 	 *
-	 * @uses filtersChecked()
+	 * @param {Event} event The click event.
 	 */
 	clearFilters: function( event ) {
 		var items = $( '.filter-group' ).find( ':checkbox' ),
diff --git a/src/js/_enqueues/wp/updates.js b/src/js/_enqueues/wp/updates.js
index ef4b47e66093e..63235ef71712c 100644
--- a/src/js/_enqueues/wp/updates.js
+++ b/src/js/_enqueues/wp/updates.js
@@ -8,26 +8,26 @@
 /* global pagenow, _wpThemeSettings */
 
 /**
- * @param {jQuery}  $                                        jQuery object.
- * @param {object}  wp                                       WP object.
- * @param {object}  settings                                 WP Updates settings.
- * @param {string}  settings.ajax_nonce                      Ajax nonce.
- * @param {object=} settings.plugins                         Base names of plugins in their different states.
- * @param {Array}   settings.plugins.all                     Base names of all plugins.
- * @param {Array}   settings.plugins.active                  Base names of active plugins.
- * @param {Array}   settings.plugins.inactive                Base names of inactive plugins.
- * @param {Array}   settings.plugins.upgrade                 Base names of plugins with updates available.
- * @param {Array}   settings.plugins.recently_activated      Base names of recently activated plugins.
- * @param {Array}   settings.plugins['auto-update-enabled']  Base names of plugins set to auto-update.
- * @param {Array}   settings.plugins['auto-update-disabled'] Base names of plugins set to not auto-update.
- * @param {object=} settings.themes                          Slugs of themes in their different states.
- * @param {Array}   settings.themes.all                      Slugs of all themes.
- * @param {Array}   settings.themes.upgrade                  Slugs of themes with updates available.
- * @param {Arrat}   settings.themes.disabled                 Slugs of disabled themes.
- * @param {Array}   settings.themes['auto-update-enabled']   Slugs of themes set to auto-update.
- * @param {Array}   settings.themes['auto-update-disabled']  Slugs of themes set to not auto-update.
- * @param {object=} settings.totals                          Combined information for available update counts.
- * @param {number}  settings.totals.count                    Holds the amount of available updates.
+ * @param {JQueryStatic} $                                        The jQuery object.
+ * @param {Object}       wp                                       WP object.
+ * @param {Object}       settings                                 WP Updates settings.
+ * @param {string}       settings.ajax_nonce                      Ajax nonce.
+ * @param {Object}       settings.plugins                         Base names of plugins in their different states.
+ * @param {Array}        settings.plugins.all                     Base names of all plugins.
+ * @param {Array}        settings.plugins.active                  Base names of active plugins.
+ * @param {Array}        settings.plugins.inactive                Base names of inactive plugins.
+ * @param {Array}        settings.plugins.upgrade                 Base names of plugins with updates available.
+ * @param {Array}        settings.plugins.recently_activated      Base names of recently activated plugins.
+ * @param {Array}        settings.plugins['auto-update-enabled']  Base names of plugins set to auto-update.
+ * @param {Array}        settings.plugins['auto-update-disabled'] Base names of plugins set to not auto-update.
+ * @param {Object}       settings.themes                          Slugs of themes in their different states.
+ * @param {Array}        settings.themes.all                      Slugs of all themes.
+ * @param {Array}        settings.themes.upgrade                  Slugs of themes with updates available.
+ * @param {Array}        settings.themes.disabled                 Slugs of disabled themes.
+ * @param {Array}        settings.themes['auto-update-enabled']   Slugs of themes set to auto-update.
+ * @param {Array}        settings.themes['auto-update-disabled']  Slugs of themes set to not auto-update.
+ * @param {Object}       settings.totals                          Combined information for available update counts.
+ * @param {number}       settings.totals.count                    Holds the amount of available updates.
  */
 (function( $, wp, settings ) {
 	var $document = $( document ),
@@ -54,7 +54,7 @@
 	 * @since 4.2.0
 	 * @deprecated 5.5.0
 	 *
-	 * @type {object}
+	 * @type {Object}
 	 */
 	wp.updates.l10n = {
 		searchResults: '',
@@ -155,7 +155,7 @@
 	 *
 	 * @since 4.2.0
 	 *
-	 * @type {bool}
+	 * @type {boolean}
 	 */
 	wp.updates.shouldRequestFilesystemCredentials = false;
 
@@ -166,18 +166,18 @@
 	 * @since 4.6.0 Added `available` property to indicate whether credentials have been provided.
 	 *
 	 * @type {Object}
-	 * @property {Object} filesystemCredentials.ftp                Holds FTP credentials.
-	 * @property {string} filesystemCredentials.ftp.host           FTP host. Default empty string.
-	 * @property {string} filesystemCredentials.ftp.username       FTP user name. Default empty string.
-	 * @property {string} filesystemCredentials.ftp.password       FTP password. Default empty string.
-	 * @property {string} filesystemCredentials.ftp.connectionType Type of FTP connection. 'ssh', 'ftp', or 'ftps'.
-	 *                                                             Default empty string.
-	 * @property {Object} filesystemCredentials.ssh                Holds SSH credentials.
-	 * @property {string} filesystemCredentials.ssh.publicKey      The public key. Default empty string.
-	 * @property {string} filesystemCredentials.ssh.privateKey     The private key. Default empty string.
-	 * @property {string} filesystemCredentials.fsNonce            Filesystem credentials form nonce.
-	 * @property {bool}   filesystemCredentials.available          Whether filesystem credentials have been provided.
-	 *                                                             Default 'false'.
+	 * @property {Object}  filesystemCredentials.ftp                Holds FTP credentials.
+	 * @property {string}  filesystemCredentials.ftp.host           FTP host. Default empty string.
+	 * @property {string}  filesystemCredentials.ftp.username       FTP user name. Default empty string.
+	 * @property {string}  filesystemCredentials.ftp.password       FTP password. Default empty string.
+	 * @property {string}  filesystemCredentials.ftp.connectionType Type of FTP connection. 'ssh', 'ftp', or 'ftps'.
+	 *                                                              Default empty string.
+	 * @property {Object}  filesystemCredentials.ssh                Holds SSH credentials.
+	 * @property {string}  filesystemCredentials.ssh.publicKey      The public key. Default empty string.
+	 * @property {string}  filesystemCredentials.ssh.privateKey     The private key. Default empty string.
+	 * @property {string}  filesystemCredentials.fsNonce            Filesystem credentials form nonce.
+	 * @property {boolean} filesystemCredentials.available          Whether filesystem credentials have been provided.
+	 *                                                              Default 'false'.
 	 */
 	wp.updates.filesystemCredentials = {
 		ftp:       {
@@ -200,7 +200,7 @@
 	 * @since 4.2.0
 	 * @since 4.6.0 More accurately named `ajaxLocked`.
 	 *
-	 * @type {bool}
+	 * @type {boolean}
 	 */
 	wp.updates.ajaxLocked = false;
 
@@ -209,7 +209,7 @@
 	 *
 	 * @since 4.6.0
 	 *
-	 * @type {function}
+	 * @type {Function}
 	 */
 	wp.updates.adminNotice = wp.template( 'wp-updates-admin-notice' );
 
@@ -240,14 +240,14 @@
 	 *
 	 * @since 4.6.0
 	 *
-	 * @param {Object}  data
-	 * @param {*=}      data.selector      Optional. Selector of an element to be replaced with the admin notice.
-	 * @param {string=} data.id            Optional. Unique id that will be used as the notice's id attribute.
-	 * @param {string=} data.className     Optional. Class names that will be used in the admin notice.
-	 * @param {string=} data.message       Optional. The message displayed in the notice.
-	 * @param {number=} data.successes     Optional. The amount of successful operations.
-	 * @param {number=} data.errors        Optional. The amount of failed operations.
-	 * @param {Array=}  data.errorMessages Optional. Error messages of failed operations.
+	 * @param {Object} data
+	 * @param {*}      [data.selector]      Optional. Selector of an element to be replaced with the admin notice.
+	 * @param {string} [data.id]            Optional. Unique id that will be used as the notice's id attribute.
+	 * @param {string} [data.className]     Optional. Class names that will be used in the admin notice.
+	 * @param {string} [data.message]       Optional. The message displayed in the notice.
+	 * @param {number} [data.successes]     Optional. The amount of successful operations.
+	 * @param {number} [data.errors]        Optional. The amount of failed operations.
+	 * @param {Array}  [data.errorMessages] Optional. Error messages of failed operations.
 	 *
 	 */
 	wp.updates.addAdminNotice = function( data ) {
@@ -333,9 +333,9 @@
 	 *
 	 * @since 4.6.0
 	 *
-	 * @param {Object}  response
-	 * @param {Array=}  response.debug     Optional. Debug information.
-	 * @param {string=} response.errorCode Optional. Error code for an error that occurred.
+	 * @param {Object} response
+	 * @param {Array}  [response.debug]     Optional. Debug information.
+	 * @param {string} [response.errorCode] Optional. Error code for an error that occurred.
 	 */
 	wp.updates.ajaxAlways = function( response ) {
 		if ( ! response.errorCode || 'unable_to_connect_to_filesystem' !== response.errorCode ) {
@@ -427,16 +427,16 @@
 	 *
 	 * @since 6.5.0
 	 *
-	 * @param {Object}  data               An object of data to use for the button.
-	 * @param {string}  data.slug          The plugin's slug.
-	 * @param {string}  data.text          The text to use for the button.
-	 * @param {string}  data.ariaLabel     The value for the button's aria-label attribute. An empty string removes the attribute.
-	 * @param {string=} data.status        Optional. An identifier for the status.
-	 * @param {string=} data.removeClasses Optional. A space-separated list of classes to remove from the button.
-	 * @param {string=} data.addClasses    Optional. A space-separated list of classes to add to the button.
-	 * @param {string=} data.href          Optional. The button's URL.
-	 * @param {string=} data.pluginName    Optional. The plugin's name.
-	 * @param {string=} data.plugin        Optional. The plugin file, relative to the plugins directory.
+	 * @param {Object} data                 An object of data to use for the button.
+	 * @param {string} data.slug            The plugin's slug.
+	 * @param {string} data.text            The text to use for the button.
+	 * @param {string} data.ariaLabel       The value for the button's aria-label attribute. An empty string removes the attribute.
+	 * @param {string} [data.status]        Optional. An identifier for the status.
+	 * @param {string} [data.removeClasses] Optional. A space-separated list of classes to remove from the button.
+	 * @param {string} [data.addClasses]    Optional. A space-separated list of classes to add to the button.
+	 * @param {string} [data.href]          Optional. The button's URL.
+	 * @param {string} [data.pluginName]    Optional. The plugin's name.
+	 * @param {string} [data.plugin]        Optional. The plugin file, relative to the plugins directory.
 	 */
 	wp.updates.setCardButtonStatus = function( data ) {
 		var target = window.parent === window ? null : window.parent;
@@ -476,11 +476,11 @@
 	 * @since 4.2.0
 	 * @since 4.6.0 More accurately named `updatePlugin`.
 	 *
-	 * @param {Object}               args         Arguments.
-	 * @param {string}               args.plugin  Plugin basename.
-	 * @param {string}               args.slug    Plugin slug.
-	 * @param {updatePluginSuccess=} args.success Optional. Success callback. Default: wp.updates.updatePluginSuccess
-	 * @param {updatePluginError=}   args.error   Optional. Error callback. Default: wp.updates.updatePluginError
+	 * @param {Object}              args           Arguments.
+	 * @param {string}              args.plugin    Plugin basename.
+	 * @param {string}              args.slug      Plugin slug.
+	 * @param {updatePluginSuccess} [args.success] Optional. Success callback. Default: wp.updates.updatePluginSuccess
+	 * @param {updatePluginError}   [args.error]   Optional. Error callback. Default: wp.updates.updatePluginError
 	 * @return {$.promise} A jQuery promise that represents the request,
 	 *                     decorated with an abort() method.
 	 */
@@ -619,12 +619,12 @@
 	 * @since 4.2.0
 	 * @since 4.6.0 More accurately named `updatePluginError`.
 	 *
-	 * @param {Object}  response              Response from the server.
-	 * @param {string}  response.slug         Slug of the plugin to be updated.
-	 * @param {string}  response.plugin       Basename of the plugin to be updated.
-	 * @param {string=} response.pluginName   Optional. Name of the plugin to be updated.
-	 * @param {string}  response.errorCode    Error code for the error that occurred.
-	 * @param {string}  response.errorMessage The error that occurred.
+	 * @param {Object} response              Response from the server.
+	 * @param {string} response.slug         Slug of the plugin to be updated.
+	 * @param {string} response.plugin       Basename of the plugin to be updated.
+	 * @param {string} response.pluginName   Optional. Name of the plugin to be updated.
+	 * @param {string} response.errorCode    Error code for the error that occurred.
+	 * @param {string} response.errorMessage The error that occurred.
 	 */
 	wp.updates.updatePluginError = function( response ) {
 		var $pluginRow, $card, $message, errorMessage, buttonText, ariaLabel,
@@ -736,10 +736,10 @@
 	 *
 	 * @since 4.6.0
 	 *
-	 * @param {Object}                args         Arguments.
-	 * @param {string}                args.slug    Plugin identifier in the WordPress.org Plugin repository.
-	 * @param {installPluginSuccess=} args.success Optional. Success callback. Default: wp.updates.installPluginSuccess
-	 * @param {installPluginError=}   args.error   Optional. Error callback. Default: wp.updates.installPluginError
+	 * @param {Object}               args         Arguments.
+	 * @param {string}               args.slug    Plugin identifier in the WordPress.org Plugin repository.
+	 * @param {installPluginSuccess} args.success Optional. Success callback. Default: wp.updates.installPluginSuccess
+	 * @param {installPluginError}   args.error   Optional. Error callback. Default: wp.updates.installPluginError
 	 * @return {$.promise} A jQuery promise that represents the request,
 	 *                     decorated with an abort() method.
 	 */
@@ -851,11 +851,11 @@
 	 *
 	 * @since 4.6.0
 	 *
-	 * @param {Object}  response              Response from the server.
-	 * @param {string}  response.slug         Slug of the plugin to be installed.
-	 * @param {string=} response.pluginName   Optional. Name of the plugin to be installed.
-	 * @param {string}  response.errorCode    Error code for the error that occurred.
-	 * @param {string}  response.errorMessage The error that occurred.
+	 * @param {Object} response              Response from the server.
+	 * @param {string} response.slug         Slug of the plugin to be installed.
+	 * @param {string} response.pluginName   Optional. Name of the plugin to be installed.
+	 * @param {string} response.errorCode    Error code for the error that occurred.
+	 * @param {string} response.errorMessage The error that occurred.
 	 */
 	wp.updates.installPluginError = function( response ) {
 		var $card   = $( '.plugin-card-' + response.slug + ', #plugin-information-footer' ),
@@ -922,10 +922,10 @@
 	 *
 	 * @since 6.5.0
 	 *
-	 * @param {Object}                          args         Arguments.
-	 * @param {string}                          args.slug    Plugin identifier in the WordPress.org Plugin repository.
-	 * @param {checkPluginDependenciesSuccess=} args.success Optional. Success callback. Default: wp.updates.checkPluginDependenciesSuccess
-	 * @param {checkPluginDependenciesError=}   args.error   Optional. Error callback. Default: wp.updates.checkPluginDependenciesError
+	 * @param {Object}                         args         Arguments.
+	 * @param {string}                         args.slug    Plugin identifier in the WordPress.org Plugin repository.
+	 * @param {checkPluginDependenciesSuccess} args.success Optional. Success callback. Default: wp.updates.checkPluginDependenciesSuccess
+	 * @param {checkPluginDependenciesError}   args.error   Optional. Error callback. Default: wp.updates.checkPluginDependenciesError
 	 * @return {$.promise} A jQuery promise that represents the request,
 	 *                     decorated with an abort() method.
 	 */
@@ -1014,11 +1014,11 @@
 	 *
 	 * @since 6.5.0
 	 *
-	 * @param {Object}  response              Response from the server.
-	 * @param {string}  response.slug         Slug of the plugin to be checked.
-	 * @param {string=} response.pluginName   Optional. Name of the plugin to be checked.
-	 * @param {string}  response.errorCode    Error code for the error that occurred.
-	 * @param {string}  response.errorMessage The error that occurred.
+	 * @param {Object} response              Response from the server.
+	 * @param {string} response.slug         Slug of the plugin to be checked.
+	 * @param {string} response.pluginName   Optional. Name of the plugin to be checked.
+	 * @param {string} response.errorCode    Error code for the error that occurred.
+	 * @param {string} response.errorMessage The error that occurred.
 	 */
 	wp.updates.checkPluginDependenciesError = function( response ) {
 		var $message = $( '.plugin-card-' + response.slug + ', #plugin-information-footer' ).find( '.install-now' ),
@@ -1069,12 +1069,12 @@
 	 *
 	 * @since 6.5.0
 	 *
-	 * @param {Object}                 args         Arguments.
-	 * @param {string}                 args.name    The name of the plugin.
-	 * @param {string}                 args.slug    Plugin identifier in the WordPress.org Plugin repository.
-	 * @param {string}                 args.plugin  The plugin file, relative to the plugins directory.
-	 * @param {activatePluginSuccess=} args.success Optional. Success callback. Default: wp.updates.activatePluginSuccess
-	 * @param {activatePluginError=}   args.error   Optional. Error callback. Default: wp.updates.activatePluginError
+	 * @param {Object}                args         Arguments.
+	 * @param {string}                args.name    The name of the plugin.
+	 * @param {string}                args.slug    Plugin identifier in the WordPress.org Plugin repository.
+	 * @param {string}                args.plugin  The plugin file, relative to the plugins directory.
+	 * @param {activatePluginSuccess} args.success Optional. Success callback. Default: wp.updates.activatePluginSuccess
+	 * @param {activatePluginError}   args.error   Optional. Error callback. Default: wp.updates.activatePluginError
 	 * @return {$.promise} A jQuery promise that represents the request,
 	 *                     decorated with an abort() method.
 	 */
@@ -1177,11 +1177,11 @@
 	 *
 	 * @since 6.5.0
 	 *
-	 * @param {Object}  response              Response from the server.
-	 * @param {string}  response.slug         Slug of the plugin to be activated.
-	 * @param {string=} response.pluginName   Optional. Name of the plugin to be activated.
-	 * @param {string}  response.errorCode    Error code for the error that occurred.
-	 * @param {string}  response.errorMessage The error that occurred.
+	 * @param {Object} response              Response from the server.
+	 * @param {string} response.slug         Slug of the plugin to be activated.
+	 * @param {string} response.pluginName   Optional. Name of the plugin to be activated.
+	 * @param {string} response.errorCode    Error code for the error that occurred.
+	 * @param {string} response.errorMessage The error that occurred.
 	 */
 	wp.updates.activatePluginError = function( response ) {
 		var $message = $( '.plugin-card-' + response.slug + ', #plugin-information-footer' ).find( '.activating-message' ),
@@ -1270,11 +1270,11 @@
 	 *
 	 * @since 4.6.0
 	 *
-	 * @param {Object}  response              Response from the server.
-	 * @param {string}  response.slug         Slug of the plugin to be installed.
-	 * @param {string=} response.pluginName   Optional. Name of the plugin to be installed.
-	 * @param {string}  response.errorCode    Error code for the error that occurred.
-	 * @param {string}  response.errorMessage The error that occurred.
+	 * @param {Object} response              Response from the server.
+	 * @param {string} response.slug         Slug of the plugin to be installed.
+	 * @param {string} response.pluginName   Optional. Name of the plugin to be installed.
+	 * @param {string} response.errorCode    Error code for the error that occurred.
+	 * @param {string} response.errorMessage The error that occurred.
 	 */
 	wp.updates.installImporterError = function( response ) {
 		var errorMessage = sprintf(
@@ -1321,11 +1321,11 @@
 	 *
 	 * @since 4.6.0
 	 *
-	 * @param {Object}               args         Arguments.
-	 * @param {string}               args.plugin  Basename of the plugin to be deleted.
-	 * @param {string}               args.slug    Slug of the plugin to be deleted.
-	 * @param {deletePluginSuccess=} args.success Optional. Success callback. Default: wp.updates.deletePluginSuccess
-	 * @param {deletePluginError=}   args.error   Optional. Error callback. Default: wp.updates.deletePluginError
+	 * @param {Object}              args         Arguments.
+	 * @param {string}              args.plugin  Basename of the plugin to be deleted.
+	 * @param {string}              args.slug    Slug of the plugin to be deleted.
+	 * @param {deletePluginSuccess} args.success Optional. Success callback. Default: wp.updates.deletePluginSuccess
+	 * @param {deletePluginError}   args.error   Optional. Error callback. Default: wp.updates.deletePluginError
 	 * @return {$.promise} A jQuery promise that represents the request,
 	 *                     decorated with an abort() method.
 	 */
@@ -1480,12 +1480,12 @@
 	 *
 	 * @since 4.6.0
 	 *
-	 * @param {Object}  response              Response from the server.
-	 * @param {string}  response.slug         Slug of the plugin to be deleted.
-	 * @param {string}  response.plugin       Base name of the plugin to be deleted
-	 * @param {string=} response.pluginName   Optional. Name of the plugin to be deleted.
-	 * @param {string}  response.errorCode    Error code for the error that occurred.
-	 * @param {string}  response.errorMessage The error that occurred.
+	 * @param {Object} response              Response from the server.
+	 * @param {string} response.slug         Slug of the plugin to be deleted.
+	 * @param {string} response.plugin       Base name of the plugin to be deleted
+	 * @param {string} response.pluginName   Optional. Name of the plugin to be deleted.
+	 * @param {string} response.errorCode    Error code for the error that occurred.
+	 * @param {string} response.errorMessage The error that occurred.
 	 */
 	wp.updates.deletePluginError = function( response ) {
 		var $plugin, $pluginUpdateRow,
@@ -1537,10 +1537,10 @@
 	 *
 	 * @since 4.6.0
 	 *
-	 * @param {Object}              args         Arguments.
-	 * @param {string}              args.slug    Theme stylesheet.
-	 * @param {updateThemeSuccess=} args.success Optional. Success callback. Default: wp.updates.updateThemeSuccess
-	 * @param {updateThemeError=}   args.error   Optional. Error callback. Default: wp.updates.updateThemeError
+	 * @param {Object}             args         Arguments.
+	 * @param {string}             args.slug    Theme stylesheet.
+	 * @param {updateThemeSuccess} args.success Optional. Success callback. Default: wp.updates.updateThemeSuccess
+	 * @param {updateThemeError}   args.error   Optional. Error callback. Default: wp.updates.updateThemeError
 	 * @return {$.promise} A jQuery promise that represents the request,
 	 *                     decorated with an abort() method.
 	 */
@@ -1708,10 +1708,10 @@
 	 *
 	 * @since 4.6.0
 	 *
-	 * @param {Object}               args
-	 * @param {string}               args.slug    Theme stylesheet.
-	 * @param {installThemeSuccess=} args.success Optional. Success callback. Default: wp.updates.installThemeSuccess
-	 * @param {installThemeError=}   args.error   Optional. Error callback. Default: wp.updates.installThemeError
+	 * @param {Object}              args
+	 * @param {string}              args.slug    Theme stylesheet.
+	 * @param {installThemeSuccess} args.success Optional. Success callback. Default: wp.updates.installThemeSuccess
+	 * @param {installThemeError}   args.error   Optional. Error callback. Default: wp.updates.installThemeError
 	 * @return {$.promise} A jQuery promise that represents the request,
 	 *                     decorated with an abort() method.
 	 */
@@ -1900,10 +1900,10 @@
 	 *
 	 * @since 4.6.0
 	 *
-	 * @param {Object}              args
-	 * @param {string}              args.slug    Theme stylesheet.
-	 * @param {deleteThemeSuccess=} args.success Optional. Success callback. Default: wp.updates.deleteThemeSuccess
-	 * @param {deleteThemeError=}   args.error   Optional. Error callback. Default: wp.updates.deleteThemeError
+	 * @param {Object}             args
+	 * @param {string}             args.slug    Theme stylesheet.
+	 * @param {deleteThemeSuccess} args.success Optional. Success callback. Default: wp.updates.deleteThemeSuccess
+	 * @param {deleteThemeError}   args.error   Optional. Error callback. Default: wp.updates.deleteThemeError
 	 * @return {$.promise} A jQuery promise that represents the request,
 	 *                     decorated with an abort() method.
 	 */
@@ -2147,7 +2147,7 @@
 	 *
 	 * @since 4.2.0
 	 *
-	 * @param {Event=} event Optional. Event interface.
+	 * @param {Event} event Optional. Event interface.
 	 */
 	wp.updates.requestFilesystemCredentials = function( event ) {
 		if ( false === wp.updates.filesystemCredentials.available ) {
@@ -2169,7 +2169,7 @@
 	 *
 	 * @since 4.6.0
 	 *
-	 * @param {Event=} event Optional. Event interface.
+	 * @param {Event} event Optional. Event interface.
 	 */
 	wp.updates.maybeRequestFilesystemCredentials = function( event ) {
 		if ( wp.updates.shouldRequestFilesystemCredentials && ! wp.updates.ajaxLocked ) {
@@ -2325,12 +2325,13 @@
 	 *
 	 * If the response deems to be invalid, an admin notice is being displayed.
 	 *
-	 * @param {(Object|string)} response              Response from the server.
-	 * @param {function=}       response.always       Optional. Callback for when the Deferred is resolved or rejected.
-	 * @param {string=}         response.statusText   Optional. Status message corresponding to the status code.
-	 * @param {string=}         response.responseText Optional. Request response as text.
-	 * @param {string}          action                Type of action the response is referring to. Can be 'delete',
-	 *                                                'update' or 'install'.
+	 * @param {(Object|string)} response                Response from the server.
+	 * @param {Function}        [response.always]       Optional. Callback for when the Deferred is resolved or rejected.
+	 * @param {string}          [response.statusText]   Optional. Status message corresponding to the status code.
+	 * @param {string}          [response.responseText] Optional. Request response as text.
+	 * @param {string}          action                  Type of action the response is referring to. Can be 'delete',
+	 *                                                  'update' or 'install'.
+	 * @return {boolean} Whether the response is valid or not.
 	 */
 	wp.updates.isValidResponse = function( response, action ) {
 		var error = __( 'An error occurred during the update process. Please try again.' ),
@@ -2421,6 +2422,7 @@
 	 * opens an "Are you sure?" alert.
 	 *
 	 * @since 4.2.0
+	 * @return {string|void} Message to display in the "Are you sure?" alert, or nothing.
 	 */
 	wp.updates.beforeunload = function() {
 		if ( wp.updates.ajaxLocked ) {
diff --git a/src/js/_enqueues/wp/util.js b/src/js/_enqueues/wp/util.js
index f6425f2178bcb..e29fd3be462e8 100644
--- a/src/js/_enqueues/wp/util.js
+++ b/src/js/_enqueues/wp/util.js
@@ -18,7 +18,7 @@ window.wp = window.wp || {};
 	 *
 	 * @param {string} id A string that corresponds to a DOM element with an id prefixed with "tmpl-".
 	 *                    For example, "attachment" maps to "tmpl-attachment".
-	 * @return {function} A function that lazily-compiles the template requested.
+	 * @return {Function} A function that lazily-compiles the template requested.
 	 */
 	wp.template = _.memoize(function ( id ) {
 		var compiled,
@@ -60,9 +60,9 @@ window.wp = window.wp || {};
 		 *
 		 * Sends a POST request to WordPress.
 		 *
-		 * @param {(string|Object)} action The slug of the action to fire in WordPress or options passed
-		 *                                 to jQuery.ajax.
-		 * @param {Object=}         data   Optional. The data to populate $_POST with.
+		 * @param {string|Object} action The slug of the action to fire in WordPress or options passed
+		 *                               to jQuery.ajax.
+		 * @param {Object}        [data] Optional. The data to populate $_POST with.
 		 * @return {$.promise} A jQuery promise that represents the request,
 		 *                     decorated with an abort() method.
 		 */
@@ -77,9 +77,9 @@ window.wp = window.wp || {};
 		 *
 		 * Sends a POST request to WordPress.
 		 *
-		 * @param {(string|Object)} action  The slug of the action to fire in WordPress or options passed
-		 *                                  to jQuery.ajax.
-		 * @param {Object=}         options Optional. The options passed to jQuery.ajax.
+		 * @param {(string|Object)} action    The slug of the action to fire in WordPress or options passed
+		 *                                    to jQuery.ajax.
+		 * @param {Object}          [options] Optional. The options passed to jQuery.ajax.
 		 * @return {$.promise} A jQuery promise that represents the request,
 		 *                     decorated with an abort() method.
 		 */