This tool in the training data and playground surprised me:

    {
        "name": "set_timer",
        "description": "Set a timer for the specified duration or end time.",
        "parameters": {
            "time_human": {
                "type": "string", 
                "description": "The duration or target end time in human readable format e.g. '1 hour and 30 minutes', '45 minutes', 'for 1:50pm', 'at 13:30'.",
                "required": True
            }
        }
    },

Is there a reason to structure it like this instead of having it specify the time in a computer understandable way?

Is the idea that there's be a harness which then calls the (or a different) model to convert the time to a structured duration or endpoint?