docs: improved comment

Author: Anas12091101

lms/djangoapps/grades/subsection_grade.py

@@ -60,8 +60,10 @@ def show_grades(self, has_staff_access):
         Returns whether subsection scores are currently available to users with or without staff access.
         """
         if self.show_correctness == ShowCorrectness.NEVER_BUT_INCLUDE_GRADE:
+            # show_grades fn is used to determine if the grade should be included in final calculation.
             # For NEVER_BUT_INCLUDE_GRADE, show_grades returns True if the due date has passed,
-            # but correctness_available returns False.
+            # but correctness_available always returns False as we do not want to show correctness
+            # of problems to the users.
             return (self.due is None or
                     self.due < datetime.now(timezone.utc))
         return ShowCorrectness.correctness_available(self.show_correctness, self.due, has_staff_access)