updated the datatype for my arguments in the currency convert tool

app.py

@@ -20,10 +20,10 @@ def my_custom_tool(arg1:str, arg2:int)-> str: #it's import to specify the return
     return "What magic will you build ?"
 
 @tool
-def convert_currency(amount:float, from_currency:float, to_currency:float)-> float:
+def convert_currency(amount:float, from_currency:str, to_currency:str) -> float:
     """ A tool that converts a specified amount from one currency to another.
     Args:
-        amount (float): The amount of money to convert (e.g. 10.5)
+        amount (float): The amount of money to convert (e.g. 10.5).
         from_currency (str): The currency code of the source currency (e.g., 'USD').
         to_currency (str): The currency code of the target currency (e.g., 'EUR').
     """