tools.py

import ast, operator, datetime

def calculator(expression: str) -> str:
    ops = {ast.Add: operator.add, ast.Sub: operator.sub,
           ast.Mult: operator.mul, ast.Div: operator.truediv,
           ast.Pow: operator.pow, ast.USub: operator.neg}
    def ev(node):
        if isinstance(node, ast.Constant):
            return node.value
        if isinstance(node, ast.BinOp):
            return ops[type(node.op)](ev(node.left), ev(node.right))
        if isinstance(node, ast.UnaryOp):
            return ops[type(node.op)](ev(node.operand))
        raise ValueError("unsupported expression")
    try:
        return str(ev(ast.parse(expression, mode="eval").body))
    except Exception as e:
        return f"error: {e}"

def word_count(text: str) -> str:
    return str(len(text.split()))

def get_time(_: str = "") -> str:
    return datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S")

TOOLS = {"calculator": calculator, "word_count": word_count, "get_time": get_time}

TOOL_DESCRIPTIONS = """
- calculator(expression): evaluates a math expression, e.g. "12*7+1"
- word_count(text): counts words in a string
- get_time(): returns the current date and time
"""