A hit means that the "drug" under test interacted with the target site on the molecule.
If the drug is intended to interact with the molecule ... that is a good thing.
If the drug is NOT intended to interact with the molecule (a side effect) then that is not a good thing.
Generally speaking, we look for drugs with hits that interact in a "good" way with a "bad" molecule ...
in some jobs, usually methodology, we may be testing those candidate drugs to ensure that they DO NOT interact with the molecules required for life.
mondo