> ## Documentation Index
> Fetch the complete documentation index at: https://phidatainc.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Tool Decorator with Hook

> Attach a custom duration-logging hook to a tool via @tool(tool_hooks=[...]) to time each tool call.

Show how to decorate a custom hook with a tool execution hook.

```python tool_decorator_with_hook.py theme={null}
"""Show how to decorate a custom hook with a tool execution hook."""

import json
import time
from typing import Any, Callable, Dict

import httpx
from agno.agent import Agent
from agno.tools import tool
from agno.utils.log import logger

# ---------------------------------------------------------------------------
# Create Agent
# ---------------------------------------------------------------------------


def duration_logger_hook(
    function_name: str, function_call: Callable, arguments: Dict[str, Any]
):
    """Log the duration of the function call"""
    start_time = time.time()

    result = function_call(**arguments)

    end_time = time.time()
    duration = end_time - start_time
    logger.info(f"Function {function_name} took {duration:.2f} seconds to execute")
    return result


@tool(tool_hooks=[duration_logger_hook])
def get_top_hackernews_stories(agent: Agent) -> str:
    num_stories = agent.dependencies.get("num_stories", 5) if agent.dependencies else 5

    # Fetch top story IDs
    response = httpx.get("https://hacker-news.firebaseio.com/v0/topstories.json")
    story_ids = response.json()

    final_stories = {}
    for story_id in story_ids[:num_stories]:
        story_response = httpx.get(
            f"https://hacker-news.firebaseio.com/v0/item/{story_id}.json"
        )
        story = story_response.json()
        if "text" in story:
            story.pop("text", None)
        final_stories[story_id] = story

    return json.dumps(final_stories)


agent = Agent(
    dependencies={
        "num_stories": 2,
    },
    tools=[get_top_hackernews_stories],
    markdown=True,
)

# ---------------------------------------------------------------------------
# Run Agent
# ---------------------------------------------------------------------------
if __name__ == "__main__":
    agent.print_response("What are the top hackernews stories?", stream=True)
```

## Run the Example

<Steps>
  <Snippet file="create-venv-step.mdx" />

  <Step title="Install dependencies">
    ```bash theme={null}
    uv pip install -U agno openai
    ```
  </Step>

  <Step title="Export your OpenAI API key">
    <CodeGroup>
      ```bash Mac/Linux theme={null}
      export OPENAI_API_KEY="your_openai_api_key_here"
      ```

      ```bash Windows theme={null}
      $Env:OPENAI_API_KEY="your_openai_api_key_here"
      ```
    </CodeGroup>
  </Step>

  <Step title="Run the example">
    Save the code above as `tool_decorator_with_hook.py`, then run:

    ```bash theme={null}
    python tool_decorator_with_hook.py
    ```
  </Step>
</Steps>

Full source: [cookbook/91\_tools/tool\_decorator/tool\_decorator\_with\_hook.py](https://github.com/agno-agi/agno/blob/main/cookbook/91_tools/tool_decorator/tool_decorator_with_hook.py)