Remove back-compat branch in evaluateSubAgentStop's stop decision (#616)

lastAssistantText is now required so every call path gets the
incomplete-report nudge instead of letting omitted text complete
a tool-less turn unconditionally.

Author: TheGreatAxios

CHANGELOG.md

@@ -11,6 +11,15 @@ matching `## [X.Y.Z]` section (plus install instructions). Do not maintain
 parallel copies under `docs/` or `scripts/notes/`. At cut time: rename
 `## [Unreleased]` to `## [X.Y.Z] - YYYY-MM-DD`, then run the release script.
 
+## [Unreleased]
+
+### Agent
+
+- `evaluateSubAgentStop` now always requires the final assistant text; the
+  omitted-text branch that unconditionally completed a tool-less turn is
+  removed, so every call path gets the `incomplete-report` nudge and salvage
+  when a tool-using run ends in envelope-less narration.
+
 ## [0.2.109] - 2026-08-24
 
 ### Agent

src/subagent/index.test.ts

@@ -148,14 +148,15 @@ describe("sub-agent stop helpers", () => {
     expect(subAgentTurnLimitExceeded(1_000_000, Infinity)).toBe(false);
   });
 
-  test("evaluateSubAgentStop returns complete when tools were used and the final turn has none", () => {
+  test("evaluateSubAgentStop returns incomplete-report when the final turn has no tool calls and no envelope", () => {
     expect(
       evaluateSubAgentStop({
         hasToolCalls: false,
         turnsCompleted: 2,
         maxTurns: 10,
+        lastAssistantText: "",
       }),
-    ).toBe("complete");
+    ).toBe("incomplete-report");
   });
 
   const SUMMARY_ONLY_NARRATION = [
@@ -293,6 +294,7 @@ describe("sub-agent stop helpers", () => {
     expect(
       evaluateSubAgentStop({
         hasToolCalls: true,
+        lastAssistantText: "",
         turnsCompleted: 40,
         maxTurns: 60,
         thrashState: thrash,
@@ -304,6 +306,7 @@ describe("sub-agent stop helpers", () => {
     expect(
       evaluateSubAgentStop({
         hasToolCalls: true,
+        lastAssistantText: "",
         turnsCompleted: 10,
         maxTurns: 10,
       }),
@@ -314,6 +317,7 @@ describe("sub-agent stop helpers", () => {
     expect(
       evaluateSubAgentStop({
         hasToolCalls: true,
+        lastAssistantText: "",
         turnsCompleted: 5,
         maxTurns: 10,
       }),
@@ -333,6 +337,7 @@ describe("sub-agent stop helpers", () => {
     expect(
       evaluateSubAgentStop({
         hasToolCalls: true,
+        lastAssistantText: "",
         turnsCompleted: 10,
         maxTurns: 10,
         thrashState: thrash,
@@ -344,6 +349,7 @@ describe("sub-agent stop helpers", () => {
     expect(
       evaluateSubAgentStop({
         hasToolCalls: true,
+        lastAssistantText: "",
         turnsCompleted: 8,
         maxTurns: 10,
         thrashState: EMPTY_THRASH_STATE,
@@ -353,6 +359,7 @@ describe("sub-agent stop helpers", () => {
     expect(
       evaluateSubAgentStop({
         hasToolCalls: true,
+        lastAssistantText: "",
         turnsCompleted: 9,
         maxTurns: 10,
         thrashState: EMPTY_THRASH_STATE,
@@ -361,6 +368,7 @@ describe("sub-agent stop helpers", () => {
     expect(
       evaluateSubAgentStop({
         hasToolCalls: true,
+        lastAssistantText: "",
         turnsCompleted: 10,
         maxTurns: 10,
         thrashState: EMPTY_THRASH_STATE,
@@ -378,6 +386,7 @@ describe("sub-agent stop helpers", () => {
     expect(
       evaluateSubAgentStop({
         hasToolCalls: true,
+        lastAssistantText: "",
         turnsCompleted: 5,
         maxTurns: 20,
         thrashState: thrash,
@@ -649,6 +658,7 @@ describe("thrash edge cases", () => {
   const stop = (turnsCompleted: number, maxTurns: number, thrashState = EMPTY_THRASH_STATE) =>
     evaluateSubAgentStop({
       hasToolCalls: true,
+      lastAssistantText: "",
       turnsCompleted,
       maxTurns,
       thrashState,

src/subagent/stop-policy.ts

@@ -83,9 +83,9 @@ export type SubAgentStopReason =
  * caller to inject a wrap-up / redirect nudge and keep running; turn-budget
  * remains reachable afterward. A tool-less turn (including one that never
  * called a tool at all) completes only when the assistant text has a
- * four-heading envelope (Summary, Findings, Blockers, Paths). Omitting
- * `lastAssistantText` still completes (back-compat). Missing envelope nudges
- * once (`incomplete-report`) then salvages (`incomplete-report-stop`).
+ * four-heading envelope (Summary, Findings, Blockers, Paths). Missing
+ * envelope nudges once (`incomplete-report`) then salvages
+ * (`incomplete-report-stop`).
  * When `requireEvidence` is set (CritiqueDirector), an empty `readCounts`
  * is not complete even with all four headings — same incomplete-report
  * nudge then salvage, so a wrap-up envelope cannot fake a real review.
@@ -105,20 +105,17 @@ export function evaluateSubAgentStop(input: {
    */
   requireEvidence?: boolean;
   /**
-   * Final assistant text of this turn. When omitted, a tool-less turn after
-   * tools still completes (back-compat for existing unit tests). When provided,
-   * a missing four-heading envelope (Summary/Findings/Blockers/Paths) nudges
-   * once then salvages.
+   * Final assistant text of this turn. A missing four-heading envelope
+   * (Summary/Findings/Blockers/Paths) nudges once then salvages.
    */
-  lastAssistantText?: string;
+  lastAssistantText: string;
   /** True after the one-shot incomplete-report wrap-up nudge has been injected. */
   incompleteReportNudgeFired?: boolean;
 }): SubAgentStopReason | null {
-  // A tool-less turn is complete only with a report envelope (or when
-  // lastAssistantText is omitted). CritiqueDirector additionally requires at
-  // least one read/search in thrashState.readCounts.
+  // A tool-less turn is complete only with a report envelope. CritiqueDirector
+  // additionally requires at least one read/search in thrashState.readCounts.
   if (!input.hasToolCalls) {
-    if (input.lastAssistantText !== undefined && !hasReportEnvelope(input.lastAssistantText)) {
+    if (!hasReportEnvelope(input.lastAssistantText)) {
       return input.incompleteReportNudgeFired === true
         ? "incomplete-report-stop"
         : "incomplete-report";