Update app.py

app.py

@@ -14,7 +14,7 @@ def calculator(expression: str)-> str: # Returns a string result
     A tool that evaluates a mathematical expression using the Wolfram Alpha API.
     
     Args:
-        expression (str): A mathematical expression to solve (e.g., "1+2", "3*5").
+        expression: A mathematical expression to solve (e.g., "1+2", "3*5").
         
     Returns:
         str: The result of the calculation if successful, or an error message if the request fails.