That's a reasonable attempt at defining what over-commenting is by trying to define what it isn't. However, it's not a very subjective definition. I tend to write fairly long comments anywhere I think it might help me in the future. I can't predict what I'll forget. I can't predict what will help me understand my code in the future. I have almost never looked at a comment and wished that someone would have written less (aside from comments that just mimic the code, e.g. "increment x"). It's almost always the opposite. I almost always wish I (or the other dev) had left more information.

Literate programming comes to mind as an extreme counter example of not enough comments. https://en.wikipedia.org/wiki/Donald_Knuth#Literate_programm...