Update app.py

app.py

@@ -8,25 +8,26 @@ 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 calculator(operation: str) -> str:
-    """
-    A simple calculator that evaluates a basic arithmetic operation given as a string.
-
+    """A simple calculator tool that safely evaluates basic math expressions.
+    
     Args:
-        operation (str): A mathematical expression (e.g., '5 + 3', '10 - 2', '4 * 7', '20 / 5').
-
+        operation: The mathematical expression to evaluate (e.g., "2 + 2", "5 * 3"). 
+                  Supports basic operations (+, -, *, /) and parentheses.
+    
     Returns:
-        str: The result of the calculation as a string.
-
-    Raises:
-        ValueError: If the operation is invalid or cannot be computed.
+        str: The result of the calculation or an error message
     """
     try:
-        result = eval(operation)
-        return str(result)
+        allowed_chars = set("0123456789+-*/ .()")
+        if not all(c in allowed_chars for c in operation):
+            return "Error: Only basic math operations allowed"
+        result = eval(operation, {"__builtins__": {}})
+        return f"Result: {result}"
     except Exception as e:
-        raise ValueError(f"Invalid operation: {operation}. Error: {str(e)}")
+        return f"Error calculating {operation}: {str(e)}"
 
 @tool
 def get_current_time_in_timezone(timezone: str) -> str: