Tool Decorator for Anthropic SDK

A Python decorator that simplifies the creation of tool definitions for the Anthropic SDK.

Overview

This package provides a @tool decorator that automatically generates Anthropic-compatible tool definitions from Python functions. It extracts parameter types, descriptions, and other metadata directly from function signatures and docstrings.

Installation

pip install tool-decorator

Usage

Basic Usage

from tool_decorator import tool

@tool(description="Search for information on the web")
def search_web(query: str, max_results: int = 10):
    """
    Performs a web search and returns results.

    Args:
        query: The search query string
        max_results: Maximum number of results to return
    """
    # Implementation here
    pass

# Access the tool definition
tool_definition = search_web.definition

Using with Anthropic SDK

from tool_decorator import tool
from anthropic import Anthropic
from datetime import datetime

# Define a simple tool with the decorator
@tool()
def get_time(timezone: str = "UTC"):
    """
    Get the current time.

    Args:
        timezone: The timezone to get the time for (default: UTC)
    """
    # Simple implementation that ignores timezone for demo purposes
    current_time = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
    return {"current_time": current_time, "timezone": timezone}

# Create a client
client = Anthropic()

# Use the tool definition with the SDK
response = client.messages.create(
    model="claude-3-7-sonnet-20250219",
    max_tokens=1000,
    messages=[
        {"role": "user", "content": "What is the current time?"}
    ],
    tools=[
        get_time.definition  # Use definition attribute directly
    ]
)

# Print the response
print("Response received successfully!")
print(f"Model: {response.model}")
print("\nResponse content:")
print(response.content)

Comparison with Manual Definition

Without the decorator, you would need to manually define the tool definition:

# Manual tool definition
get_time_definition = {
    "name": "get_time",
    "description": "Get the current time.",
    "input_schema": {
        "type": "object",
        "properties": {
            "timezone": {
                "type": "string",
                "description": "The timezone to get the time for (default: UTC)",
                "default": "UTC"
            }
        },
        "required": []
    }
}

# Use with Anthropic SDK
tools=[get_time_definition]

The decorator approach automatically generates this definition from your function signature and docstring, keeping everything in sync and reducing boilerplate code.

Generated Tool Definition Format

The decorator generates tool definitions in the required schema format for the Anthropic API.

Features

• Automatically converts Python type hints to JSON Schema types
• Extracts parameter descriptions from docstrings
• Supports optional parameters with default values
• Generates Anthropic-compatible tool definitions with the required input_schema field
• Validates parameter documentation in strict mode

Development

For information on development, building, and contributing to this project, see README_DEV.md.

Requirements

• Python 3.8+

License

MIT License - See LICENSE file for details