These lines in the guidelines are all directly or directionally relevant to this kind of comment.

Be kind. Don't be snarky. Converse curiously...

Comments should get more thoughtful and substantive, not less, as a topic gets more divisive.

Don't be curmudgeonly. Thoughtful criticism is fine, but please don't be rigidly or generically negative.

Please respond to the strongest plausible interpretation of what someone says, not a weaker one that's easier to criticize. Assume good faith.

Eschew flamebait. Avoid generic tangents. Omit internet tropes.

Please don't post shallow dismissals, especially of other people's work. A good critical comment teaches us something.

Please don't pick the most provocative thing in an article or post to complain about in the thread. Find something interesting to respond to instead.

If a story is spam or off-topic, flag it. Don't feed egregious comments by replying; flag them instead. If you flag, please don't also comment that you did.