I usually leave comments when I flag/vote to close, but I don't always do it, so when I read this title I though that it was addressed to me, due to some recent cases that I not remember if were on this site or anothe were I didn't left a comment.

While I think that might be worthy to leave comments asking for specific details I strongly disagree making leaving comments for closing flags/votes as a "obligation". Also I don't think that the lack of comment should be a reason to vote to keep a question open when it clearly should be closed as *needs details / is unclear*.

The **Ask Question** page already show a modal to new users that they should discard before be able to fill anything

[![Ask question modal for new users][1]][1]

Then the fields already have help, and the side panel have tips, as is mendtioned in the above modal.

Then it's asked the the user to review their question to review it before posting providing guidance about what they should review. 

If they ignore all that help (rethoric question ahead) what tell us that the OP will read the comments?

P.S. The modal might be customized, i.e., to point to FAQs with guidance about the typical details required for the most common questions. Personally I think that questions about using *application software* should mention what was found in the official help and why it didn't meet the OP needs.

  [1]: https://i.sstatic.net/vzFAA.png