The screw is in free failure and will need to be coated.  Overall condition is poor but it could possibly prevent leaks as it sits but to be safe we need to coat the screw.

This roof screw is in pretty good shape and may not need to be coated.

The screws have been coated and it is in bad shape and will need to be re-coated to prevent it from leaking.

These laps need to be coated with Aldo, and they will also need to be scraped and cleaned as necessary to prepare the substrate.