From 41bdb43db977c1c3000b7ed5769fc41eb2f9a50e Mon Sep 17 00:00:00 2001
From: Alexandr Smirnov <a.smirnov@dwteam.ru>
Date: Mon, 1 Jun 2026 10:59:10 +0300
Subject: [PATCH] fix(ask_user_question): add minLength/maxLength to header
 JSON Schema

Add minLength: 1 and maxLength: 12 constraints to the header property in
the ask_user_question tool's JSON Schema. This prevents the LLM from
generating headers longer than 12 characters before the tool call is made,
reducing runtime rejections.

Also adds a snapshot-style test that asserts the schema constraints are
present, catching future regressions where the limits could be dropped.

Runtime validation (lines 318-319) is kept as a safety net for callers that
bypass the schema.
---
 .../core/src/tools/askUserQuestion.test.ts     | 18 ++++++++++++++++++
 packages/core/src/tools/askUserQuestion.ts     |  4 +++-
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/packages/core/src/tools/askUserQuestion.test.ts b/packages/core/src/tools/askUserQuestion.test.ts
index 63709baf93..e75ee56536 100644
--- a/packages/core/src/tools/askUserQuestion.test.ts
+++ b/packages/core/src/tools/askUserQuestion.test.ts
@@ -36,6 +36,24 @@ describe('AskUserQuestionTool', () => {
     });
   });
 
+  describe('JSON Schema', () => {
+    it('should enforce header maxLength 12 and minLength 1 in the schema', () => {
+      const schema = tool.schema.parametersJsonSchema as Record<
+        string,
+        unknown
+      >;
+      const questions = (schema['properties'] ?? {}) as Record<string, unknown>;
+      const items = (questions['questions'] ?? {}) as Record<string, unknown>;
+      const questionProps = (items['items'] ?? {}) as Record<string, unknown>;
+      const header = (questionProps['properties'] ?? {}) as Record<
+        string,
+        unknown
+      >;
+      expect(header['maxLength']).toBe(12);
+      expect(header['minLength']).toBe(1);
+    });
+  });
+
   describe('validateToolParams', () => {
     it('should accept valid params with single question', () => {
       const params = {
diff --git a/packages/core/src/tools/askUserQuestion.ts b/packages/core/src/tools/askUserQuestion.ts
index d6e571cf33..dafd017ce8 100644
--- a/packages/core/src/tools/askUserQuestion.ts
+++ b/packages/core/src/tools/askUserQuestion.ts
@@ -79,8 +79,10 @@ const askUserQuestionToolSchemaData: FunctionDeclaration = {
             },
             header: {
               description:
-                'Very short label displayed as a chip/tag (max 12 chars). Examples: "Auth method", "Library", "Approach".',
+                'Required: 1-12 characters. Very short label displayed as a chip/tag. Examples: "Auth method", "Library", "Approach".',
               type: 'string',
+              minLength: 1,
+              maxLength: 12,
             },
             options: {
               description: