Question

Your customer-support agent calls a `check_order_status` tool. The backend times out and returns no data. You want Claude to acknowledge the failure to the user and possibly suggest a retry, rather than fabricating an order status. When you send the tool result back in the next user-role message, what is the correct way to communicate this outcome to Claude?

Accepted Answer

Return a `tool_result` content block containing the error message and set `is_error` to true, matching the original `tool_use_id`.

Answer

Omit the `tool_result` block entirely so Claude infers that the tool failed from the missing response.

Answer

Send a plain assistant-role message telling Claude the tool failed, then continue the conversation.

Answer

Return a `tool_result` block with a made-up placeholder status like 'unknown' so the schema stays valid.