Advertise present, manage_goal, manage_tasks, and lsp conditionally

present now stays fully dispatchable but is discovered via tool_search
instead of riding every request at 2,793 chars — the second-largest
core tool schema for a feature most sessions never touch.

manage_goal is advertised only when the session was resumed with an
already-active goal, and lsp only when a language server was resolved
at startup. Both facts are captured once, before the first inference
call, since the wire tools array is a provider cache prefix: toggling
either mid-session would force a re-prefill worse than the schema
bytes saved. manage_tasks stays unconditional in both session modes —
the goal-kickoff sequence calls manage_goal then manage_tasks back to
back, so gating the second would trade one tool_search round trip for
two.

Author: TheGreatAxios

src/agent/lsp-availability.test.ts

@@ -0,0 +1,46 @@
+import { describe, test, expect, afterEach } from "bun:test";
+import { mkdtemp, mkdir, writeFile, rm } from "node:fs/promises";
+import { tmpdir } from "node:os";
+import path from "node:path";
+import { detectLanguageServerAvailable } from "./lsp-availability.js";
+
+const dirsToClean: string[] = [];
+
+async function tempProject(): Promise<string> {
+  const dir = await mkdtemp(path.join(tmpdir(), "corbits-lsp-availability-"));
+  dirsToClean.push(dir);
+  return dir;
+}
+
+afterEach(async () => {
+  await Promise.all(dirsToClean.splice(0).map((dir) => rm(dir, { recursive: true, force: true })));
+});
+
+async function seedTsserver(dir: string): Promise<void> {
+  const tsserverDir = path.join(dir, "node_modules", "typescript", "lib");
+  await mkdir(tsserverDir, { recursive: true });
+  await writeFile(path.join(tsserverDir, "tsserver.js"), "");
+}
+
+describe("detectLanguageServerAvailable", () => {
+  test("false when typescript is not installed in the project", async () => {
+    const dir = await tempProject();
+    expect(detectLanguageServerAvailable(dir)).toBe(false);
+  });
+
+  test("true when tsserver is resolvable and a local .bin binary exists", async () => {
+    const dir = await tempProject();
+    await seedTsserver(dir);
+    const bin = path.join(dir, "node_modules", ".bin", "typescript-language-server");
+    await mkdir(path.dirname(bin), { recursive: true });
+    await writeFile(bin, "#!/usr/bin/env node\n");
+    expect(detectLanguageServerAvailable(dir)).toBe(true);
+  });
+
+  test("the real project checkout has a language server available", () => {
+    // This repo itself installs typescript and typescript-language-server as
+    // devDependencies, so detection against the actual cwd is a live check
+    // that the two-condition logic agrees with what createLSPPlugin would find.
+    expect(detectLanguageServerAvailable(process.cwd())).toBe(true);
+  });
+});

src/agent/lsp-availability.ts

@@ -0,0 +1,15 @@
+import { existsSync } from "node:fs";
+import path from "node:path";
+
+// Mirrors the sole server @intx/tools-lsp registers today (Typescript):
+// spawning requires a resolvable tsserver plus a reachable language-server
+// binary. Checked once at session start via the filesystem and PATH — never
+// by spawning a server — because the `lsp` tool's advertisement is baked into
+// the wire tools array for the life of the session (see tool-search.ts).
+export function detectLanguageServerAvailable(cwd: string): boolean {
+  const tsserverPath = path.join(cwd, "node_modules", "typescript", "lib", "tsserver.js");
+  if (!existsSync(tsserverPath)) return false;
+  const localBin = path.join(cwd, "node_modules", ".bin", "typescript-language-server");
+  if (existsSync(localBin)) return true;
+  return Bun.which("typescript-language-server") !== null;
+}

src/agent/prompts.ts

@@ -1,7 +1,19 @@
 import type { EnvironmentInfo } from "./environment.js";
 import type { SkillSummary } from "../extensions/skills.js";
 import type { SessionMode } from "../config/session-mode.js";
-import { coreToolNamesForSessionMode, CORE_TOOL_NAMES } from "./tool-search.js";
+import {
+  coreToolNamesForSessionMode,
+  CORE_TOOL_NAMES,
+  type ToolAvailability,
+} from "./tool-search.js";
+
+// Advertise every gated core tool when the caller has no session-start facts
+// (tests, ad-hoc prompt previews). Real sessions always pass their detected
+// availability — see tui/runner.ts and exec/runner.ts.
+const DEFAULT_TOOL_AVAILABILITY: ToolAvailability = {
+  hasGoalAtLaunch: true,
+  languageServerAvailable: true,
+};
 import { PRODUCT_NAME, SETTINGS_DIR_NAME } from "../branding.js";
 
 // Fallback tool list for sub-agent prompts when the caller does not pass the
@@ -295,10 +307,11 @@ export function buildChatSystemPrompt(
   baseOverride?: string,
   skills: readonly SkillSummary[] = [],
   sessionMode: SessionMode = "orchestrator",
+  toolAvailability: ToolAvailability = DEFAULT_TOOL_AVAILABILITY,
 ): string {
   const sections = [
     baseSection(baseOverride, sessionMode),
-    buildAvailableTools(coreToolNamesForSessionMode(sessionMode)),
+    buildAvailableTools(coreToolNamesForSessionMode(sessionMode, toolAvailability)),
   ];
   if (skills.length > 0) sections.push(buildSkillsSection(skills));
   sections.push(contextSection(env));

src/agent/tool-search.test.ts

@@ -6,10 +6,21 @@ import {
   createActivatedToolTracker,
   advertisedTools,
   advertisedToolNamesForSessionMode,
+  coreToolNamesForSessionMode,
   CORE_TOOL_NAMES,
   CATALOG_TOOL_NAMES,
+  type ToolAvailability,
 } from "./tool-search.js";
 
+const FULL_AVAILABILITY: ToolAvailability = {
+  hasGoalAtLaunch: true,
+  languageServerAvailable: true,
+};
+const NO_AVAILABILITY: ToolAvailability = {
+  hasGoalAtLaunch: false,
+  languageServerAvailable: false,
+};
+
 const defs: ToolDefinition[] = [
   { name: "read_file", description: "read a file", inputSchema: { type: "object", properties: {}, required: [] } },
   { name: "web_search", description: "search the web for pages", inputSchema: { type: "object", properties: {}, required: [] } },
@@ -55,10 +66,49 @@ describe("createToolIndex", () => {
   });
 
   test("orchestrator mode advertises task and search_agents; single mode omits them", () => {
-    expect(advertisedToolNamesForSessionMode("orchestrator")).toContain("task");
-    expect(advertisedToolNamesForSessionMode("orchestrator")).toContain("search_agents");
-    expect(advertisedToolNamesForSessionMode("single")).not.toContain("task");
-    expect(advertisedToolNamesForSessionMode("single")).not.toContain("search_agents");
+    expect(advertisedToolNamesForSessionMode("orchestrator", FULL_AVAILABILITY)).toContain("task");
+    expect(advertisedToolNamesForSessionMode("orchestrator", FULL_AVAILABILITY)).toContain("search_agents");
+    expect(advertisedToolNamesForSessionMode("single", FULL_AVAILABILITY)).not.toContain("task");
+    expect(advertisedToolNamesForSessionMode("single", FULL_AVAILABILITY)).not.toContain("search_agents");
+  });
+
+  test("manage_tasks is advertised in both session modes regardless of availability", () => {
+    expect(coreToolNamesForSessionMode("single", NO_AVAILABILITY)).toContain("manage_tasks");
+    expect(coreToolNamesForSessionMode("orchestrator", NO_AVAILABILITY)).toContain("manage_tasks");
+  });
+
+  test("present is never in the advertised core set — discovered via tool_search only", () => {
+    expect(CORE_TOOL_NAMES).not.toContain("present");
+    expect(coreToolNamesForSessionMode("orchestrator", FULL_AVAILABILITY)).not.toContain("present");
+  });
+
+  test("manage_goal is advertised only when the session starts with a goal", () => {
+    expect(
+      coreToolNamesForSessionMode("orchestrator", { hasGoalAtLaunch: true, languageServerAvailable: true }),
+    ).toContain("manage_goal");
+    expect(
+      coreToolNamesForSessionMode("orchestrator", { hasGoalAtLaunch: false, languageServerAvailable: true }),
+    ).not.toContain("manage_goal");
+  });
+
+  test("lsp is advertised only when a language server was detected at startup", () => {
+    expect(
+      coreToolNamesForSessionMode("orchestrator", { hasGoalAtLaunch: false, languageServerAvailable: true }),
+    ).toContain("lsp");
+    expect(
+      coreToolNamesForSessionMode("orchestrator", { hasGoalAtLaunch: false, languageServerAvailable: false }),
+    ).not.toContain("lsp");
+  });
+
+  test("ask_operator is advertised regardless of session mode or availability", () => {
+    expect(coreToolNamesForSessionMode("single", NO_AVAILABILITY)).toContain("ask_operator");
+    expect(coreToolNamesForSessionMode("orchestrator", NO_AVAILABILITY)).toContain("ask_operator");
+  });
+
+  test("the advertised set is deterministic — repeat calls with the same inputs are identical", () => {
+    const first = coreToolNamesForSessionMode("orchestrator", NO_AVAILABILITY);
+    const second = coreToolNamesForSessionMode("orchestrator", NO_AVAILABILITY);
+    expect(second).toEqual(first);
   });
 
   test("returns nothing for an empty query", () => {
@@ -122,9 +172,11 @@ describe("advertisedTools", () => {
   ];
 
   test("single session mode omits multi-agent tools from the wire prefix", () => {
-    const names = advertisedTools(registry, [], advertisedToolNamesForSessionMode("single")).map(
-      (d) => d.name,
-    );
+    const names = advertisedTools(
+      registry,
+      [],
+      advertisedToolNamesForSessionMode("single", FULL_AVAILABILITY),
+    ).map((d) => d.name);
     expect(names).not.toContain("task");
     expect(names).not.toContain("search_agents");
     expect(names).toContain("read_file");
@@ -186,6 +238,23 @@ describe("advertisedTools", () => {
     expect(names.slice(tailIdx)).toEqual(["mcp__acme__do", "mcp__linear__create_issue"]);
   });
 
+  test("the built-in prefix is byte-identical across repeated turns of the same session", () => {
+    // Session-start availability is computed once and must never be
+    // re-evaluated per turn — simulate several turns by calling with the same
+    // captured prefix and confirm the wire array never drifts.
+    const prefix = advertisedToolNamesForSessionMode("orchestrator", {
+      hasGoalAtLaunch: false,
+      languageServerAvailable: true,
+    });
+    const turn1 = JSON.stringify(advertisedTools(registry, [], prefix));
+    const turn2 = JSON.stringify(advertisedTools(registry, [], prefix));
+    const turn3 = JSON.stringify(advertisedTools(registry, ["mcp__linear__create_issue"], prefix));
+    expect(turn2).toBe(turn1);
+    // Growth from a mid-session discovery only appends — the prefix itself
+    // (everything before the activated tail) still matches turn 1 exactly.
+    expect(turn3.startsWith(turn1.slice(0, -1))).toBe(true);
+  });
+
   test("tool_search never returns an already-advertised built-in", () => {
     for (const name of [...CORE_TOOL_NAMES, ...CATALOG_TOOL_NAMES]) {
       expect(index.search(name)).not.toContain(name);

src/agent/tool-search.ts

@@ -10,6 +10,11 @@ import { sessionModeEnablesSubAgents } from "../config/session-mode.js";
 // registered and dispatchable but discovered on demand via tool_search, keeping
 // the per-turn context small. Shared by the system prompt and the advertised-set
 // gate so the two never drift.
+//
+// `present` is deliberately absent: most sessions never render a view, and at
+// 2,793 chars it is the second-largest schema on the wire. It stays fully
+// dispatchable — the model finds it via tool_search when a session actually
+// needs it.
 export const CORE_TOOL_NAMES: readonly string[] = [
   "read_file",
   "edit_file",
@@ -18,7 +23,6 @@ export const CORE_TOOL_NAMES: readonly string[] = [
   "ask_operator",
   "manage_tasks",
   "manage_goal",
-  "present",
   "tool_search",
   "use_skill",
   "search_agents",
@@ -29,17 +33,44 @@ export const CORE_TOOL_NAMES: readonly string[] = [
   "task",
 ];
 
-const MULTI_AGENT_CORE_TOOL_NAMES: readonly string[] = ["search_agents", "task"];
+const ORCHESTRATOR_ONLY_TOOL_NAMES: readonly string[] = ["search_agents", "task"];
+
+// Session-start facts that gate a core tool's advertisement. Each must be
+// knowable once, before the first inference call, and must never change for
+// the life of the session — the tools array is a provider cache prefix (see
+// ADVERTISED_TOOL_NAMES below), so a value that could flip mid-session (e.g.
+// "is a goal active right now") would force a re-prefill worse than the
+// schema bytes it saves. `manage_tasks` is intentionally NOT gated here: the
+// goal-kickoff sequence (see goalKickoffUserMessage in ./goal.ts) instructs
+// the model to call manage_goal then manage_tasks back to back, so hiding
+// manage_tasks would trade one tool_search round trip for two.
+export type ToolAvailability = {
+  // Whether the session was resumed with an active/paused/budget-limited goal
+  // already persisted — not whether one exists at the current instant.
+  hasGoalAtLaunch: boolean;
+  // Whether a language server was resolvable for this project at startup —
+  // not whether one currently responds.
+  languageServerAvailable: boolean;
+};
 
-export function coreToolNamesForSessionMode(mode: SessionMode): readonly string[] {
-  if (!sessionModeEnablesSubAgents(mode)) {
-    return CORE_TOOL_NAMES.filter((name) => !MULTI_AGENT_CORE_TOOL_NAMES.includes(name));
-  }
-  return CORE_TOOL_NAMES;
+export function coreToolNamesForSessionMode(
+  mode: SessionMode,
+  availability: ToolAvailability,
+): readonly string[] {
+  const orchestratorEnabled = sessionModeEnablesSubAgents(mode);
+  return CORE_TOOL_NAMES.filter((name) => {
+    if (!orchestratorEnabled && ORCHESTRATOR_ONLY_TOOL_NAMES.includes(name)) return false;
+    if (name === "manage_goal") return availability.hasGoalAtLaunch;
+    if (name === "lsp") return availability.languageServerAvailable;
+    return true;
+  });
 }
 
-export function advertisedToolNamesForSessionMode(mode: SessionMode): readonly string[] {
-  return [...coreToolNamesForSessionMode(mode), ...CATALOG_TOOL_NAMES];
+export function advertisedToolNamesForSessionMode(
+  mode: SessionMode,
+  availability: ToolAvailability,
+): readonly string[] {
+  return [...coreToolNamesForSessionMode(mode, availability), ...CATALOG_TOOL_NAMES];
 }
 
 // Built-in file/search tools advertised alongside the core set. They carry full
@@ -52,13 +83,16 @@ export const CATALOG_TOOL_NAMES: readonly string[] = [
   "list_dir",
 ];
 
-// The complete set of built-in tools whose schemas are always on the wire, in a
-// deterministic order. Provider prompt caches are prefix caches keyed on the
-// tools array (it sits before system + messages), so this order must never shift
-// between turns — a reordered or grown array re-prefills the whole request.
+// The maximal set of built-in tools — every gate open — in a deterministic
+// order, used as the tool_search exclusion list and as a fallback prefix for
+// callers with no session-start availability facts. Provider prompt caches
+// are prefix caches keyed on the tools array (it sits before system +
+// messages), so this order must never shift between turns — a reordered or
+// grown array re-prefills the whole request.
 //
-// Primary TUI sessions should pass `advertisedToolNamesForSessionMode(sessionMode)`
-// as the `builtInPrefix` to `advertisedTools` — not this constant alone.
+// Primary TUI/exec sessions should pass
+// `advertisedToolNamesForSessionMode(sessionMode, toolAvailability)` as the
+// `builtInPrefix` to `advertisedTools` — not this constant alone.
 export const ADVERTISED_TOOL_NAMES: readonly string[] = [
   ...CORE_TOOL_NAMES,
   ...CATALOG_TOOL_NAMES,

src/agent/tools.ts

@@ -33,7 +33,7 @@ import {
 import type { ToolWatchdogConfig } from "../tui/tool-execution-watchdog.js";
 import type { SessionMode } from "../config/session-mode.js";
 import { sessionModeEnablesSubAgents } from "../config/session-mode.js";
-import { advertisedToolNamesForSessionMode } from "./tool-search.js";
+import { advertisedToolNamesForSessionMode, type ToolAvailability } from "./tool-search.js";
 import type { ProviderCatalogEntry } from "../config/index.js";
 import type { AgentProfile } from "./profiles.js";
 import {
@@ -109,6 +109,11 @@ export type AgentToolsetArgs = {
   isWorkflowActive?: () => boolean;
   // Primary session mode: single-agent sessions omit sub-agent tooling.
   sessionMode?: SessionMode;
+  // Session-start facts gating manage_goal/lsp advertisement. Omitted callers
+  // (tests, ad-hoc toolset construction) get both advertised, matching prior
+  // behavior. Real sessions always pass their detected values — see
+  // tool-search.ts for why these must be fixed for the session's life.
+  toolAvailability?: ToolAvailability;
   // When a goal governor is live, manage_goal mutates its acceptance checklist.
   getGoalGovernor?: () => GoalGovernor | null;
   // When provided, the agent gets a `task` tool that delegates to autonomous
@@ -176,11 +181,12 @@ export async function createAgentToolset(args: AgentToolsetArgs): Promise<AgentT
     getBlobReader,
     sessionMode = "orchestrator",
     shellEnv,
+    toolAvailability = { hasGoalAtLaunch: true, languageServerAvailable: true },
   } = args;
   const sessionBlobReader =
     getBlobReader !== undefined ? createLazyBlobReader(getBlobReader) : undefined;
   const subAgentsEnabled = sessionModeEnablesSubAgents(sessionMode);
-  const advertisedBuiltIns = advertisedToolNamesForSessionMode(sessionMode);
+  const advertisedBuiltIns = advertisedToolNamesForSessionMode(sessionMode, toolAvailability);
 
   const inheritedMcpTools: AgentTool[] = [];
 

src/exec/runner.ts

@@ -37,7 +37,9 @@ import {
   advertisedToolNamesForSessionMode,
   advertisedTools,
   createActivatedToolTracker,
+  type ToolAvailability,
 } from "../agent/tool-search.js";
+import { detectLanguageServerAvailable } from "../agent/lsp-availability.js";
 import { normalizeToolDefinitionsForProvider } from "../agent/tool-schema-normalize.js";
 import { resolveSessionMode, type SessionMode } from "../config/session-mode.js";
 import { createSubAgentSessionStore, type SubAgentProvider } from "../subagent/index.js";
@@ -304,6 +306,13 @@ export async function runExec(config: Config): Promise<ExecResult> {
     const subAgentSessions = createSubAgentSessionStore();
     const shellTimeout = shellTimeoutFromSettings(config.settings);
     const toolWatchdog = toolWatchdogFromSettings(config.settings);
+    // Exec has no goal governor (headless — no /goal), so a goal never starts
+    // at launch here. lsp is still worth detecting: exec sessions read/edit
+    // TypeScript projects same as the TUI.
+    const toolAvailability: ToolAvailability = {
+      hasGoalAtLaunch: false,
+      languageServerAvailable: detectLanguageServerAvailable(config.cwd),
+    };
 
     let currentAgent: Agent | null = null;
 
@@ -324,6 +333,7 @@ export async function runExec(config: Config): Promise<ExecResult> {
       isWorkflowActive: () => false,
       onOperatorGate: (question, options) => promptOperator(question, options, interactive),
       sessionMode,
+      toolAvailability,
       ...(config.mcpServers !== undefined ? { mcpServers: config.mcpServers } : {}),
       mcpServersSource: config.mcpServersSource ?? "none",
       projectTrust,
@@ -361,9 +371,10 @@ export async function runExec(config: Config): Promise<ExecResult> {
         ? { systemPromptExtensions: config.systemPromptExtensions }
         : {}),
       sessionMode,
+      toolAvailability,
     });
 
-    const advertisedBuiltInPrefix = advertisedToolNamesForSessionMode(sessionMode);
+    const advertisedBuiltInPrefix = advertisedToolNamesForSessionMode(sessionMode, toolAvailability);
     const activatedToolNames = createActivatedToolTracker();
     // Advertise then family-gate wire schemas (kimi gets a non-recursive present).
     const computeAdvertised = (all: readonly ToolDefinition[]): ToolDefinition[] =>