Well, I’m not sure any of the current characteristic identifiers for being an avatar or a human angel are very helpful. In fact, I think the idea of a single set of markers is rather unhelpful.
If you are, then you are. If you are not, then you are not. How do you identify anything except against the familiar notions that you have in place? What if the world was very different to the way it appears? What if nothing was as it seemed? How then would you “know” for sure without a doubt that what you see is what is?
Probably a more important question is, why do you want to know? What would being an avatar do for you? Would it mean a more peaceful, purposeful or practical experience? Would being told you are an avatar help you to make sense of what’s going on for you in a way that eases the pressure of being different or inexplicable?