worth your/its salt
worth one's salt
Fig. worth (in productivity) what it costs to keep or support one. We decided that you are worth your salt, and you can stay on as office clerk. You're not worth your salt. Pack up!
worth your saltgood or competent at the job or profession specified.
2000 Saga Magazine Every place setting is measured with a ruler because no butler worth his salt wants to get to the end of a table with say, four settings left, and nowhere to put them.
ˌworth your/its ˈsaltdeserving respect, especially because you do your job well: Any teacher worth his salt knows that students who enjoy a lesson learn the most.This may refer to the fact that in Roman times soldiers were given an allowance of salt as part of their pay. The Latin word salarium (= the money given to Roman soldiers to buy salt) is the origin of the word ‘salary’.
worth (one's) salt
Efficient and capable.