nanobot/agent/loop.py

@@ -636,8 +636,43 @@ class AgentLoop:
                     args_str = json.dumps(tool_call.arguments, ensure_ascii=False)
                     logger.info(f"Tool call: {tool_call.name}({args_str[:200]})")
                     result = await self.tools.execute(tool_call.name, tool_call.arguments)
+
+                    # Handle different result types (same logic as main handler)
+                    if isinstance(result, ToolResult):
+                        # Native Anthropic tool result
+                        # Add text content
+                        if result.output:
+                            text_content = result.output
+                        elif result.error:
+                            text_content = f"Error: {result.error}"
+                        else:
+                            text_content = ""
+
+                        # If both output and error, combine them
+                        if result.output and result.error:
+                            text_content = f"{result.output}\n\nError: {result.error}"
+
+                        # Note: Image handling for system messages not needed
+                        # (system messages don't render images to users)
+                        # But we should still log if present
+                        if result.base64_image:
+                            logger.warning(
+                                f"Tool {tool_call.name} returned image in system message context - "
+                                "images not supported here"
+                            )
+
+                        tool_content = text_content
+
+                    elif isinstance(result, CLIResult):
+                        # CLI-style tool result (text editor)
+                        tool_content = result.output
+
+                    else:
+                        # Legacy string result from function tools
+                        tool_content = result
+
                     messages = self.context.add_tool_result(
-                        messages, tool_call.id, tool_call.name, result
+                        messages, tool_call.id, tool_call.name, tool_content
                     )
                 # Interleaved CoT: reflect before next action (skip when thinking is active)
                 if not getattr(self.provider, 'thinking_budget', 0):