fix: explicit tool result instructions to guide model response

- Changed vague 'Provide your final answer now' to specific per-tool instructions
- read: 'READ THIS FILE CONTENT ALOUD to the user'
- write: 'CONFIRM to the user that the file was created'
- bash: 'SUMMARIZE the output above to answer the user's request'
- Other tools: 'Use the result shown above to answer the user's request'
- Format tool result message with clear 'Tool Result (name):' header and explicit instruction
- This should fix models ignoring tool results or giving generic responses
- All 41 tests passing

src/api/chat_handlers.py

@@ -414,15 +414,22 @@ async def handle_chat_completion(
         for i, ((tool_name, tool_result), tc) in enumerate(zip(tool_results, tool_calls_parsed)):
             tool_call_id = tc.get("id", f"call_{i}")
             
-            # For the last tool (or all tools), add instruction to stop
-            if i == len(tool_results) - 1:
-                tool_message_content = (
-                    f"{tool_result}\n\n"
-                    f"IMPORTANT: You have received the tool result above. "
-                    f"DO NOT call any more tools. Provide your final answer now."
-                )
+            # Format the tool result message with explicit instructions
+            # This tells the model exactly what to do with the result
+            if tool_name == "read":
+                instruction = "The file contents are shown above. READ THIS FILE CONTENT ALOUD to the user. Do not call additional tools."
+            elif tool_name == "write":
+                instruction = "The file has been successfully written. CONFIRM to the user that the file was created with the content shown above. Do not call additional tools."
+            elif tool_name == "bash":
+                instruction = "The command has been executed. SUMMARIZE the output above to answer the user's request. Do not call additional tools."
             else:
-                tool_message_content = tool_result
+                instruction = "The tool has completed. Use the result shown above to answer the user's request. Do not call additional tools."
+            
+            tool_message_content = (
+                f"Tool Result ({tool_name}):\n"
+                f"{tool_result}\n\n"
+                f"INSTRUCTION: {instruction}"
+            )
             
             messages.append(ChatMessage(
                 role="tool",