Update app.py

app.py

@@ -16,6 +16,9 @@ HEADERS = {
 }
 
 def search_youtube(query: str) -> str:
+    """
+    a tool that accepts a query and return youtube video link with related query 
+    """
     params = {"q": query, "hl": "en", "gl": "US"}
     try:
         response = requests.get(API_URL, headers=HEADERS, params=params)