Update app.py

app.py

@@ -11,7 +11,10 @@ from Gradio_UI import GradioUI
 # Below is an example of a tool that does nothing. Amaze us with your creativity !
 @tool
 def get_market_cap(ticker_symbol: str)-> str: #it's import to specify the return type
-    # Create a Ticker object for the given symbol
+    """A tool that fetches the market cap of a stock given its ticker symbol.
+    Args:
+        ticker_symbol: A string representing a valid stock ticker symbol (e.g., 'EXPE').
+    """
     ticker = yf.Ticker(ticker_symbol)
     
     # Fetch the info dictionary