I got an answer from skelebone:
You can add a new person at Misc --> Add Person. As for the description, it is required, but it need not be in-depth. In fact, whenever I create persons for the database, I typically add "Game Designer" as the description. The language under the description box is used from other parts of the site and doesn't apply as well to game designer submissions.
Also. in the person submission, you can link the person directly to games in the database that he or she has designed or illustrated, which makes the approval process go much more smoothly.
Scott A. Reed