clarify output

tools.py

@@ -836,7 +836,7 @@ class CommutativityAnalysisTool(BaseTool):
                         involved.add(y)
 
             # Output the result as a comma-separated, alphabetically sorted list
-            result = ', '.join(sorted(involved))
+            result = "subset of S involved in any possible counter-examples: " + ', '.join(sorted(involved))
             
             return result