Agreed. I'm sure someone is working on this and can be easily applied to HN (maybe https://www.agolo.com/)

It's something we do on Lobste.rs. Its guidelines allow a short, purely-factual description just to save people time. On CompSci papers, I always put the abstract in there either whole or trimmed. Some people TL;DR the articles in their comments which happens here, too.

Allowing a super-short summary might be a good practice here, too. Especially for long articles or videos. On videos, maybe link to transcript or slides, too, so people don't have to dig them up. It's another thing I try to do over there.