tools/fallback_tool.py

from smolagents import tool

@tool
def fallback(_: str) -> str:
    """
    Returns a polite fallback message when no specific tool applies.

    Args:
        _ (str): Unused input string.

    Returns:
        str: Default fallback response.
    """
    return "I'm sorry, I couldn't find the answer to your question. Could you rephrase or try something else?"