Ah, see, I haven't seen "distinguishing features/characteristics" on an app, but yeah, it's more or less the same as "appearance". Whatever it's called, I still think it's important to have.
In the games I'm in, the app generally is the bio/profile/what-have-you. People might pretty it up with their own coding, but the information on the app is what they direct people to look at for complete info on that character. I don't think I've ever seen anyone make a different post with different information as a profile/bio. So maybe that's where our differing opinions on this are coming from -- for me, an app does need to be a good, solid, complete description of a character, because it's going to be what other players refer to when they're getting to know the character. It's why I err on the side of more detail rather than less, because as a player I always look at other people's apps in terms of seeing what my character will see, how they might interact, and so on. I guess I assume that other people will look at my app the same way I look at theirs, and so I try to be as detailed as possible so that everybody's on the same page from the beginning. :)