tool.py

from smolagents import Tool
from typing import Optional

class SimpleTool(Tool):
    name = "get_travel_duration"
    description = "Gets the travel time in car between two places."
    inputs = {"start_location":{"type":"string","description":"the place from which you start your ride"},"destination_location":{"type":"string","description":"the place of arrival"},"departure_time":{"type":"integer","nullable":True,"description":"the departure time, provide only a `datetime.datetime` if you want to specify this"}}
    output_type = "string"

    def forward(self, start_location: str, destination_location: str, departure_time: Optional[int] = None) -> str:
        """Gets the travel time in car between two places.
    
        Args:
            start_location: the place from which you start your ride
            destination_location: the place of arrival
            departure_time: the departure time, provide only a `datetime.datetime` if you want to specify this
        """
        import googlemaps # All imports are placed within the function, to allow for sharing to Hub.
        from google.colab import userdata
        import os

        gmaps = googlemaps.Client(userdata.get("GMAPS_API_KEY"))

        if departure_time is None:
            from datetime import datetime
            departure_time = datetime(2025, 1, 6, 11, 0)

        directions_result = gmaps.directions(
            start_location,
            destination_location,
            mode="transit",
            departure_time=departure_time
        )
        return directions_result[0]["legs"][0]["duration"]["text"]