> ## Documentation Index
> Fetch the complete documentation index at: https://agno-v2.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

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

**1. Install dependencies**

```bash theme={null}
uv pip install -U agno openai
```

**2. Export your OpenAI API key**

```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"
```

**3. Run the example**

Save the code above as `tool_decorator_with_hook.py`, then run:

```bash theme={null}
python tool_decorator_with_hook.py
```

Full source: [cookbook/91\_tools/tool\_decorator/tool\_decorator\_with\_hook.py](https://github.com/agno-agi/agno/blob/v3.0.4/cookbook/91_tools/tool_decorator/tool_decorator_with_hook.py)


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