Lysmata wurdemanni (aka...peppermint shrimp) is considered to be reef-safe. They are great at controlling aiptasia, however, this behavior can be redirected toward other corals and anemones. You should always keep a close eye on peps in a reef tank because of this. That being said, I have never had any trouble with mine. Their cousin, the camel shrimp, tends to be more of a coral nipper. They look very similar and I have seen some
LFS selling camel shrimp as peppermint shrimp. Just need to make sure it is, indeed, a peppermint. If it is a peppermint and does nip at your corals, it should be considered rare, but not surprising.