Snarky is a surprising word. The official definition (snide, critical) would suggest that it’s not a compliment—I certainly wouldn’t want to be called snarky in my annual employee review. In literature, however, snarkiness can be a good thing. We like witty characters who aren’t afraid to mouth off, and we live vicariously through the hero who flouts authority and just doesn’t give a crap.
To me, that’s the good kind of snarky: someone who says and does the things I can’t. Combine that attitude with the ability to use magic, and you’ve got a heck of an interesting character.