Update app.py

Try using PIL library to define Image

app.py

@@ -4,6 +4,7 @@ import requests
 import pytz
 import yaml
 from tools.final_answer import FinalAnswerTool
+from PIL import Image
 
 from Gradio_UI import GradioUI
 
@@ -51,7 +52,7 @@ def get_current_time_in_timezone(timezone: str) -> str:
         return f"Error fetching time for timezone '{timezone}': {str(e)}"
 
 @tool
-def generate_image(description: str):
+def generate_image(description: str) -> Image:
     """A tool that generates an image from a text description.
     Args:
         description: A string representing the text description to generate an image of.