By itself, Disk First Aid takes several steps to run. AutoCheck automates the entire process, stopping and posting a dialog only if a disk error is found. Otherwise, it quits Disk First Aid and itself and is out of your way by the time you've gotten a cup of coffee, and your Mac has a clean bill of health. You can set the number of times AutoCheck tries to check a busy disk, the starting interval to wait between checks of a busy disk, and the time to pause after launching before starting the whole check. The pause can be bypassed on any occasion with the Shift key.
Source code is commented.