It would be nice if there was a way for players to access current mod description in-game by pressing some key. The description would be read from the mod file, assuming mod creator put it there.

Currently players can get some idea about the mod by typing /set to look at some settings, but there's only so much info that gives you. It doesn't give info about body/joint flags, triggers, or hidden objects, and new players wouldn't even know how to interpret those attributes anyway.

yes yes yes this is an absolute must

Playing more sophisticated mods requires people know about the different triggers and effects, and you can't really be there to explain every time somebody plays your mod for the first time

I'd go as far as to say that there should be a window dedicated to this instead of something that just appears in chat, like it looks like you imply