The challenge of hard rules like this is that they're always overly restrictive. I've made multi-thousand file PRs that needed two lines of description including the title, and 5 line PRs that needed a 1hr presentation to fully explain them.
My personal guideline is that writing for humans should be done by humans.
I mean.. human judgment still applies. But as an automated first pass the clamp works in 90% of cases. I scan for correctness and make small edits here and there.