fix: tighten adjacent function response stripping

steipete · steipete · commit a52e7f2c2457 · 2026-05-15T16:41:17.000+01:00
diff --git a/src/agents/pi-embedded-helpers.sanitizeuserfacingtext.test.ts b/src/agents/pi-embedded-helpers.sanitizeuserfacingtext.test.ts
@@ -346,6 +346,13 @@ describe("sanitizeUserFacingText", () => {
     expect(sanitizeUserFacingText(input)).toBe("After");
   });
 
+  it("strips adjacent function response payloads that match explanation wording", () => {
+    const input =
+      '<function_calls><invoke name="exec">internal</invoke></function_calls><function_response> response wrapper secret</function_response>\nAfter';
+
+    expect(sanitizeUserFacingText(input)).toBe("After");
+  });
+
   it("strips dangling same-line function response payloads with leading spaces", () => {
     const input =
       'Checking. <function_calls><invoke name="exec">internal</invoke></function_calls><function_response> raw output';
diff --git a/src/shared/text/assistant-visible-text.test.ts b/src/shared/text/assistant-visible-text.test.ts
@@ -685,22 +685,25 @@ describe("stripToolCallXmlTags", () => {
     expect(stripToolCallXmlTags(input, { stripFunctionCallsXmlPayloads: true })).toBe("");
   });
 
-  it("preserves literal function_response prose after a stripped tool-call block", () => {
+  it("strips function_response-looking prose adjacent to a stripped tool-call block", () => {
     const input =
       '<tool_call>{"name":"exec"}</tool_call>\n\n<function_response> is the response wrapper.';
 
-    expect(stripToolCallXmlTags(input, { stripFunctionCallsXmlPayloads: true })).toBe(
-      "\n\n<function_response> is the response wrapper.",
-    );
+    expect(stripToolCallXmlTags(input, { stripFunctionCallsXmlPayloads: true })).toBe("\n\n");
   });
 
-  it("preserves literal closed function_response prose after a stripped tool-call block", () => {
+  it("strips closed function_response-looking prose adjacent to a stripped tool-call block", () => {
     const input =
       '<tool_call>{"name":"exec"}</tool_call>\n<function_response> is the response wrapper; close it with </function_response>.';
 
-    expect(stripToolCallXmlTags(input, { stripFunctionCallsXmlPayloads: true })).toBe(
-      "\n<function_response> is the response wrapper; close it with </function_response>.",
-    );
+    expect(stripToolCallXmlTags(input, { stripFunctionCallsXmlPayloads: true })).toBe("\n.");
+  });
+
+  it("strips adjacent function_response payloads that match explanation wording", () => {
+    const input =
+      '<function_calls><invoke name="exec">internal</invoke></function_calls><function_response> response wrapper secret</function_response>\nAfter';
+
+    expect(stripToolCallXmlTags(input, { stripFunctionCallsXmlPayloads: true })).toBe("\nAfter");
   });
 
   it("strips compact function_response wrappers while preserving same-line prose tails", () => {
diff --git a/src/shared/text/assistant-visible-text.ts b/src/shared/text/assistant-visible-text.ts
@@ -204,21 +204,6 @@ function hasSameLineContentAfterOpeningTag(text: string, tag: ParsedToolCallTag)
   return after < text.length && text[after] !== "\n" && text[after] !== "\r";
 }
 
-function isLikelyFunctionResponseTagProse(
-  text: string,
-  tag: ParsedToolCallTag,
-  closeStart: number,
-): boolean {
-  if (text[tag.end] !== " " && text[tag.end] !== "\t") {
-    return false;
-  }
-  const body = text.slice(tag.end, closeStart === -1 ? text.length : closeStart);
-  if (body.includes("\n") || body.includes("\r")) {
-    return false;
-  }
-  return /\b(?:response wrapper|wrapper syntax|xml tag|tag syntax)\b/i.test(body);
-}
-
 function isVisibleLineStart(text: string): boolean {
   let idx = text.length - 1;
   while (idx >= 0 && (text[idx] === " " || text[idx] === "\t")) {
@@ -388,7 +373,6 @@ export function stripToolCallXmlTags(
           : -1;
       const shouldStripAdjacentResult =
         isAdjacentToStrippedToolCallBlock(text, idx, lastStrippedToolCallBlockEnd) &&
-        !isLikelyFunctionResponseTagProse(text, tag, functionResponseCloseStart) &&
         (isOpeningTagFollowedByLineBreak(text, tag) ||
           functionResponseCloseStart !== -1 ||
           hasSameLineContentAfterOpeningTag(text, tag));
