Moderator commentary when rejecting a comment

I wonder if it’s possible (and practical) to have a quick sentence or few words supplied by a moderator when rejecting a comment? Obviously there are plenty of cases where it wouldn’t be required, like spam, and we’re all either aware or rapidly discover that the realtime word filter is set to US mode and can adjust our phrasing as required. Aside from that, however, I’ve had a few instances (yesterday being one, prompting this post) where a comment is rejected and the “Learn more” link to guidelines doesn’t really clarify anything. I understand the non-zero time it’d take to write those few words on rejection, but I wonder if it’d balance out with readers learning what is or isn’t acceptable, and thus put less load on anyone moderating in future?

(Not sure if this belongs here or in Help & Support, on balance I think Community Feedback is correct but please bear with me if H&S was more appropriate)