looks like a line wrasse, and if i did learn to count from your photo a six line wrasse.
so basically he will clean bugs off your corals, but not your fish.
Hope u didn't pay too much for him, they go for near 30$ in the city.
A great fish and he will for sure keep your tank clean from coepeods and bristle worms.
they have been known to clean ich but that a per fish thing, if your dont he wont, and if he does he will.
u just dont know till it happens.
http://www.aquahobby.com/marine/e_sixline.php
what you want in a cleaner wrasse
http://www.aquahobby.com/marine/e_cleaner.php
and shame on the LFS for selling you a six line when they dont have the real one in stock.