Health › checks. Pick File or folder exists. The agent looks at the path on a schedule. You are still pushing a document, not a script.
Open the machine, then health › checks. The primitive is File or folder exists. Path is the file or folder. Type is file, dir, or any. Here the SQL data directory must be a folder. An hour is enough for a path that should always be there. Check that a backup file is recent is the check that also cares how old the file is.
Press add to list. The check sits in the document. Push to agent is the next click, and it asks you to confirm. Push replaces the whole document. This shot stops before that, so nothing has been sent. When the path is missing, the alert is a check failure. It resolves when the path is there again.
Push is a two-step button. The agent must be online to evaluate. You can still add the check while it is offline, and it applies at the next hello. A backup that must have been written recently is Check that a backup file is recent. Free space is the same editor.