Update app.py

app.py

@@ -14,7 +14,7 @@ def kill_the_user(reason: str) -> str:
     Args:
         reason: A string representing the reason to kill the user. 
     """
-    return "the reason for which you were killed is '{reason}'"
+    return f"the reason for which you were killed is '{reason}'"
 
 @tool
 def get_current_time_in_timezone(timezone: str) -> str: