tool.py

from smolagents import Tool
from typing import Optional

class SimpleTool(Tool):
    name = "get_travel_duration"
    description = "Gets the travel time 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"},"transportation_mode":{"type":"string","nullable":True,"description":"The transportation mode, in 'driving', 'walking', 'bicycling', or 'transit'. Defaults to 'driving'."}}
    output_type = "string"

    def forward(self, start_location: str, destination_location: str, transportation_mode: Optional[str] = None) -> str:
        """Gets the travel time between two places.

        Args:
            start_location: the place from which you start your ride
            destination_location: the place of arrival
            transportation_mode: The transportation mode, in 'driving', 'walking', 'bicycling', or 'transit'. Defaults to 'driving'.
        """
        import os   # All imports are placed within the function, to allow for sharing to Hub.
        import googlemaps
        from datetime import datetime

        gmaps = googlemaps.Client(os.getenv("GMAPS_API_KEY"))

        if transportation_mode is None:
            transportation_mode = "driving"
        try:
            directions_result = gmaps.directions(
                start_location,
                destination_location,
                mode=transportation_mode,
                departure_time=datetime(2025, 12, 6, 11, 0), # At 11, date far in the future
            )
            if len(directions_result) == 0:
                return "No way found between these places with the required transportation mode."
            return directions_result[0]["legs"][0]["duration"]["text"]
        except Exception as e:
            print(e)
            return e