Is it okay to edit titles of questions by other users to make them more descriptive, less exaggerated or just better (eg. capitalization, grammar, spelling)?
I'm surprised this doesn't have an answer yet. Yes, it's okay, and even encouraged.
More or less the same rules apply as when editing the body of a post; in particular, don't make drastic changes to the meaning of the question. And the title should reflect the question that is more fully expressed in the body of the post.