Wrasse IS too common a name. I think a general rule of thumb is if the adult size in near the size of an adult clam, it'll likely be bad. I know this a generalization and there are exceptions, but most of the bigger wrasses (coris, thalassoma, etc.) will ultimately think that the clams look mighty tasty.
I know of someone who had a fairy wrasse that killed several clams by attacking the gills before he got it removed. Supposedly reef safe, but all individuals are different in each and every tank.