Update app.py

adding joke test agent.

app.py

@@ -8,6 +8,14 @@ from tools.final_answer import FinalAnswerTool
 from Gradio_UI import GradioUI
 
 # Below is an example of a tool that does nothing. Amaze us with your creativity !
+@tool
+def joke()-> str: #it's import to specify the return type
+    #Keep this format for the description / args / args description but feel free to modify the tool
+    """A tool that will tell a joke. 
+    
+    """
+    return "Knock Knock,"
+
 @tool
 def my_custom_tool(arg1:str, arg2:int)-> str: #it's import to specify the return type
     #Keep this format for the description / args / args description but feel free to modify the tool