1) an exclamation to express total surprise/shock/pleasure/horror/horror/dismay at or draw attention to the state of something (used in the same context like wow or fuck).
2) a superlative adjective to add legitimacy/weight to the description of something (used in the same context as legit)
1) "Alert, those ribs were dope!"; "Alert, that bitch was rude!"
Master Shake: Thanks for ruining my lunch! Which is gone by the way...
Frylock: Have you looked in the fridge?
Master Shake: Oh Brainstorm! Alert the internet we got a genius over here