Update app.py

app.py

@@ -12,7 +12,7 @@ from markdownify import markdownify
 from requests.exceptions import RequestException
 
 @tool
-def json_string_to_poster(json_string:str)-> html_string: 
+def json_string_to_poster(json_string:str)-> str: 
     """A tool that generate a poster from stringified json object 
     Args:
         json_string: stringified json data