fix bug in get_current_exchange_rate_in_USD to just return rate

app.py

@@ -19,18 +19,17 @@ def my_custom_tool(arg1:str, arg2:int)-> str: #it's import to specify the return
     return "What magic will you build ?"
 
 @tool
-def get_current_exchange_rate_in_USD(currency: str, amount: float) -> str:
+def get_current_exchange_rate_in_USD(currency: str) -> str:
     """A tool that fetches the current exchange rate for specified currency against the US Dollar (USD)
     Args:
         currency: A string representing a valid currency (e.g., 'CAD' for Canadian Dollar).
-        amount: A float representing an amount of currency to convert to USD.
     """
     data_url = 'https://open.er-api.com/v6/latest/USD'
     try:
         r = requests.get(data_url)
         rates = r.json()['rates']
         rate = rates[currency.upper()]
-        return f"{amount} units of {currency.upper()} currency is worth ${float(rate)*amount} US dollars."
+        return f"{currency.upper()} currency is worth ${rate} US dollars."
     except Exception as e:
         return f"Error fetching currency rate for '{currency}': {str(e)}"