Update app.py

app.py

@@ -19,7 +19,7 @@ def my_cutom_tool(arg1:str, arg2:int)-> str: #it's important to specify the retu
     return "What magic will you build ?"
 
 @tool
-def string_concatinator(string1: str, string2: str) > str:
+def string_concatinator(string1: str, string2: str) -> str:
     """ A tool that concats given 2 strings
     Args:
         string1: First string