IMO a big warning sign of overhoning is when the hair actually "pops" or "pings" away from the blade in the various hair tests.

There are degrees of overhoning, in the earlier stages the blade is sharper but still too weak to survive many shaves, but it may do ok for a shave or two. At greater levels of overhoning the edge gets weaker and weaker until it can't survive even one stroke. Sometimes the edge folds over like the tip of a snow ski and the edge just rides over your whiskers wiping lather off but not cutting a thing. Sometimes (usually for me) the edge folds the other way and you get something like a paper cut before the edge breaks off into your skin. And sometimes the edge will break off and tear on the hone, and you'll get this ragged-looking edge under the scope. Except that sometimes this ragged-looking edge is just microchipping because of grit in your hone, or rotten steel (ebay razors), or just really brittle steel (wacker, sta-sharp, couple of others).

I have had overhoned edges break off and embed themselves in my hone. I'll be honing along and the razor will kind of do this hop on the hone, and suddenly it's dull and there's something stuck in my hone that I've got to pick out with a magnifying glass and tweezers.