Update app.py

app.py

@@ -18,7 +18,7 @@ def my_custom_tool(arg1:str, arg2:int)-> str: #it's import to specify the return
     """
     return "What magic will you build ?"
 
-def add(a:int, b:int)-> ingt:
+def add(a:int, b:int)-> int:
     """A tool that adds two intergers
     Args:
         a: the first number