Can I pick up on your example (bolded by me to call it out) and a possible risk in play? Not to denigrate the example, but to try to connect it into how I'm thinking about things.
Yes. Always!
It seems to me that it is possible that the GM might narrate the koblds' drool and bloodshot eyes, hoping and intending to evoke a particular response and engagement from the players, only instead to trigger responses about the kobolds having had a hard night out, being stone/hungover, etc. (Similar to [MENTION=22779]Hussar[/MENTION]'s reference, I think upthread, to players making d*ck jokes.)
Sure. And, depending on the nature of the fiction, I might let that be... the kobolds will be remembered as hungover dogmen. (Indeed, it may be that the bloodshot eyes were meant to indicate that they were tired or drugged or hungover.) If I felt that it was a misunderstanding that wouldn't likely happen within the fiction, then I would gently provide additional detail: "Hmm, there's something more ominous about it than your typical frat boy after a hard night out. It has a crazed dimension, not unlike a rabid dog..."
And I can see how that response fits with your larger premise that the "dynamics of the here-and-now" are central.
On an unrelated tangent:
This is a fairly common rule of thumb to teach children in America in terms of writing; I know that they do in 5th, 6th, and 7th grade (for the most part).
Yes. Ugh. And a lot of teachers are trying to stamp it out, along with "five paragraph essays" and other simplifications that often squelch the creative joy that comes from learning to craft great writing. I know that at my K-12 school there are no students at any level who are taught that a paragraph has to have a certain number of sentences.