Alerts › scripts. Reboots is the kind for a machine that restarted. A routine restart is a notice, and warning and above skips a notice.
Open Alerts › scripts and press new trigger. Name it and choose Who is signed in. Downtime is already ticked. Reboots is clear, so a restart would not start this draft. Disk, checks, network path, Docker apps and custom metric are clear too. The floor stays at warn and above.
Tick reboots and clear downtime. A restart is the only kind that starts this script. Accounts server's disk at 92% is a disk alert, so it would not. The key box stays empty, so every restart matches, on every machine. A routine restart is recorded as a notice, and the floor is still warn and above, so that notice stays quiet until the menu beside when is info. Press save when this is the one you want. This shot stops before that. Cancel drops the draft. Run on is still these machines, and none is ticked, so a save would also need a target.
Telling a person about a restart, with no script, is Only tell them about a reboot. The floor is Only run a script for a critical alert — info is the lowest choice on that menu. A full disk is Run a script only when a disk fills. A failed check is Run a script only when a check fails.