A close examination of the exception needs to be undertaken to preclude possible issues.
First is the phrase "...parent or legal guardian of a student..."
This doesn't include the grandparents, siblings, extended family members, or coaches, of the student.
(a) A school or school property except that a parent or legal guardian of a student of the school is not precluded from carrying a concealed pistol while in a vehicle on school property, if he or she is dropping the student off at the school or picking up the child from the school. As used in this section, "school" and "school property" mean those terms as defined in section 237a of the Michigan penal code, 1931 PA 328, MCL 750.237a.
Second is the phrase "...student of the school..."
If it's not your student's school, then they are not a "student of the school" that you are on driving around on school property.
(a) A school or school property except that a parent or legal guardian of a student of the school is not precluded from carrying a concealed pistol while in a vehicle on school property, if he or she is dropping the student off at the school or picking up the child from the school. As used in this section, "school" and "school property" mean those terms as defined in section 237a of the Michigan penal code, 1931 PA 328, MCL 750.237a.
Thirdly is the phrase "... if he or she is dropping the student off at the school or picking up the child from the school."
If a parent just drives on the school property to watch child's sports and then drive's away, a violation may have occurred.
(a) A school or school property except that a parent or legal guardian of a student of the school is not precluded from carrying a concealed pistol while in a vehicle on school property, if he or she is dropping the student off at the school or picking up the child from the school. As used in this section, "school" and "school property" mean those terms as defined in section 237a of the Michigan penal code, 1931 PA 328, MCL 750.237a.