# build_tool_error_payload

> **Function** in `deepagents_code`

📖 [View in docs](https://reference.langchain.com/python/deepagents-code/_tool_stream/build_tool_error_payload)

Build the `tool.error` hook payload (schema documented in `hooks`).

## Signature

```python
build_tool_error_payload(
    tool_name: str,
) -> ToolErrorPayload
```

## Parameters

| Name | Type | Required | Description |
|------|------|----------|-------------|
| `tool_name` | `str` | Yes | The tool whose call failed or was rejected. |

## Returns

`ToolErrorPayload`

The `tool.error` payload dict.

---

[View source on GitHub](https://github.com/langchain-ai/deepagents/blob/e14e0adcbe78565ed3650e7f24b2a775d5437d25/libs/code/deepagents_code/_tool_stream.py#L640)