Function Tools

Turn any Python function into a tool with one decorator.

Function Tools allow your agent to execute your own Python functions.

Instead of only generating text, your agent can call Python code to perform actions.

Create a Function Tool#

from abagentsdk import function_tool

@function_tool
def get_weather(city: str):
    return f"The weather in {city} is sunny."

Register a Tool#

agent = Agent(
    name="Weather Assistant",
    instructions="Help users with weather information.",
    model="gemini-2.5-flash",
    tools=[get_weather]
)

Example#

response = agent.run("What's the weather in Karachi?")

print(response.content)

The SDK automatically decides when to call the tool and returns the result before generating the final response.

What Can You Build?#

• Weather APIs
• Calculators
• Database Queries
• File Management
• Email Automation
• Web Search
• External APIs
• Custom Business Logic

Best Practices#

• Keep each tool focused on one task.
• Give tools descriptive names.
• Return predictable results.
• Keep tool logic reusable.

Next Step#

Continue to Built-in Tools.