Final answer:
According to Para 2-12, comments must be made on the NCOER for a failed PT test if the failure reflects the NCO's lack of effort or disregard for standards.
Step-by-step explanation:
According to U.S. Army regulations, specifically Para 2-12, a rater should provide comments on an NCOER about observable actions and behavior, such as a failed PT test, if the failure is due to a lack of effort or a disregard for physical fitness standards. The intention behind these comments is to provide a clear and concise reflection of the Non-Commissioned Officer's (NCO's) performance and potential. A failed PT test is a significant event that can affect the NCO's overall career, and therefore, it is typically addressed in the NCOER to give a full picture of the individual's capabilities and readiness.