Just what the title says. If you slip the pick under the E,B,G strings at the 12th fret, and it's held there, your action is way too low and you probably can't get a good tone. Raise it!
The black gator is 2mm thick and something in 2.3mm-2.6mm is an acceptable range for the action on the high E string (source: Bob Holo
). Action is measured from the top of the fret to the bottom of the string at its midpoint, those 2mm picks should clear easily and fall right out.