Return a tool result

tool_use = next(b for b in response.content if b.type == "tool_use")
result = run_tool(tool_use.name, tool_use.input)   # your code

messages.append({"role": "assistant", "content": response.content})
messages.append({"role": "user", "content": [
    {"type": "tool_result", "tool_use_id": tool_use.id, "content": result},
]})