Quick
Prompt, Clever, Shrewd, Smart
noun, な adjective
A machine alert is an alert that is timed by a machine, not by a human. That is pretty quick and clever. Machines can move and think so much faster than us, after all.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
ウェイトレスってのは機敏に動くものなのに、彼女はとんでもなく鈍いんだよ。
Waitresses are supposed to move quickly, but she is ridiculously slow.