Why don't you?
It has an edit button in the UI for entering in the metadata to its database manually.
It has the option to prefer metadata already stored locally inside the container when populating its database.
It has the "match" button for interactively discovering and retrieving the metadata from an agent like IMDb or tvdb regardless of filename.
By default it tries to spare you having to do any of these things, but they put a lot of work into facilitating several alternatives when you'd rather do the work yourself.
