Enable write_todo tool and fix output function schema (#12905)

packages/core/src/config/config.ts

@@ -514,7 +514,7 @@ export class Config {
       params.truncateToolOutputLines ?? DEFAULT_TRUNCATE_TOOL_OUTPUT_LINES;
     this.enableToolOutputTruncation = params.enableToolOutputTruncation ?? true;
     this.useSmartEdit = params.useSmartEdit ?? true;
-    this.useWriteTodos = params.useWriteTodos ?? false;
+    this.useWriteTodos = params.useWriteTodos ?? true;
     this.initialUseModelRouter = params.useModelRouter ?? false;
     this.useModelRouter = this.initialUseModelRouter;
     this.disableModelRouterForAuth = params.disableModelRouterForAuth ?? [];

packages/core/src/tools/write-todos.ts

@@ -173,14 +173,48 @@ export class WriteTodosTool extends BaseDeclarativeTool<
                 },
               },
               required: ['description', 'status'],
+              additionalProperties: false,
             },
           },
         },
         required: ['todos'],
+        additionalProperties: false,
       },
     );
   }
 
+  override get schema() {
+    return {
+      name: this.name,
+      description: this.description,
+      parametersJsonSchema: this.parameterSchema,
+      responseJsonSchema: {
+        type: 'object',
+        properties: {
+          todos: {
+            type: 'array',
+            items: {
+              type: 'object',
+              properties: {
+                description: {
+                  type: 'string',
+                },
+                status: {
+                  type: 'string',
+                  enum: TODO_STATUSES,
+                },
+              },
+              required: ['description', 'status'],
+              additionalProperties: false,
+            },
+          },
+        },
+        required: ['todos'],
+        additionalProperties: false,
+      },
+    };
+  }
+
   protected override validateToolParamValues(
     params: WriteTodosToolParams,
   ): string | null {