Good question. How about this:
Appearance can be a written description (as long as it's thorough enough), a picture, or both. Background doesn't need to be super long, but should at least explain why they are where they are. The last section is a little ambiguous, but the idea is that that's where you'd put the general role the character would fill in a party, like 'fighter' or 'black mage', or you might instead have a summary of their abilities, i.e. Rei might be something like 'very agile fighter with thief skills and lightning magic'.