Update app.py

app.py

@@ -16,7 +16,13 @@ def my_custom_tool(arg1:str, arg2:int)-> str: #it's import to specify the return
         arg1: the first argument
         arg2: the second argument
     """
-    return "What magic will you build ?"
+    arg1_length = len(arg1)
+    if arg2 < arg1_length:
+        return arg1[:arg2]
+    elif arg2 == arg1_length:
+        return "Bingo!"
+    else:
+        return arg1
 
 @tool
 def get_current_time_in_timezone(timezone: str) -> str: