v1.12 track B.2: codecontext tool wrappers + tests

apps/server/src/services/inference.ts

@@ -621,10 +621,26 @@ async function executeToolCall(
   }
   const parsed = tool.inputSchema.safeParse(toolCall.args);
   if (!parsed.success) {
+    // v1.12 Track B.2: enrich the zod-reject path so the model sees a
+    // one-line, tool-named hint ("tool 'search_symbols' rejected — query:
+    // Required") instead of a JSON blob of flatten output. Higher recovery
+    // rate on the next turn; doom-loop guard still bounds infinite retries.
+    // The cast is because tool.inputSchema is ZodType<unknown>, so zod can't
+    // statically narrow flatten()'s fieldErrors key set — but the runtime
+    // shape is the standard { formErrors: string[]; fieldErrors: Record<...> }.
+    const flatten = parsed.error.flatten() as {
+      formErrors: string[];
+      fieldErrors: Record<string, string[] | undefined>;
+    };
+    const fieldErrors = Object.entries(flatten.fieldErrors)
+      .map(([field, errs]) => `${field}: ${errs?.[0] ?? 'invalid'}`)
+      .join('; ');
+    const formError = flatten.formErrors[0];
+    const hint = fieldErrors || formError || 'unknown validation error';
     return {
       output: null,
       truncated: false,
-      error: `invalid input: ${JSON.stringify(parsed.error.flatten())}`,
+      error: `tool '${toolCall.name}' rejected — ${hint}`,
     };
   }
   try {