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This example demonstrates how to use strict tool validation with structured outputs. Strict tool use ensures that tool parameters strictly follow the input schema, providing additional validation when using tools alongside structured outputs.

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Code

structured_output_strict_tools.py
from agno.agent import Agent
from agno.models.anthropic import Claude
from agno.tools import Function
from pydantic import BaseModel


class WeatherInfo(BaseModel):
    """Structured output schema for weather information."""

    location: str
    temperature: float
    unit: str
    condition: str


def get_weather(location: str, unit: str = "celsius") -> str:
    temp = 72 if unit == "fahrenheit" else 22
    return f"Weather in {location}: {temp}°{unit}, Sunny"


# Create function with strict mode enabled
weather_tool = Function(
    name="get_weather",
    description="Get current weather information for a location",
    parameters={
        "type": "object",
        "properties": {
            "location": {
                "type": "string",
                "description": "The city and state, e.g. San Francisco, CA",
            },
            "unit": {
                "type": "string",
                "enum": ["celsius", "fahrenheit"],
                "description": "Temperature unit",
            },
        },
        "required": ["location"],
        "additionalProperties": False,
    },
    strict=True,  # Enable strict mode for validated tool parameters
    entrypoint=get_weather,
)

# Agent with both structured outputs and strict tool
agent = Agent(
    model=Claude(id="claude-sonnet-4-5-20250929"),
    tools=[weather_tool],
    output_schema=WeatherInfo,
    description="You help users get weather information.",
)

# The agent will use strict tool validation and return structured output
agent.print_response("What's the weather like in San Francisco?")

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Usage

1

Create a virtual environment

Open the Terminal and create a python virtual environment.
python3 -m venv .venv
source .venv/bin/activate
2

Set your API key

export ANTHROPIC_API_KEY=xxx
3

Install libraries

pip install -U anthropic agno
4

Run Agent

python structured_output_strict_tools.py