So rarity of word use makes something literary? I don’t agree with that at all.I would call that a literary description. You are certainly using several words that would almost never appear in conversation - "gaunt" "rictus", "scans about" "wields". I mean, "rictus", as far as I an tell, doesn't even appear in the top 10000 of most common English words. Nor does "gaunt". These are quite obviously words that would only appear in writing (or close enough to only that it can see only on a clear day). Which, to me, qualifies it as an attempt at "literary" rather than conversation.
The description isn’t a bad one by any means. Again, this goes back to “non-literary does not equal bland”. All it attempts to do is describe the creature to the players.
What about the elevator example that you snipped? What did you think of that?
If the description itself contained attempts at creativity or art, then I think that’s what would be an attempt at literary quality.
To put it another way, let’s say two kids ride their skateboard to the store, a few blocks from where they live. One kid simply rides there, avoiding hazards and navigating the streets and sidewalks and all the obstacles. Still takes skill, right?
The other kid makes the same trip but includes a bunch of tricks along the way....he ollies from the curb over a pothole and railgrinds along the back of a bench and does a bunch of kickflips and so on.
Both kids make the same trip, both trips still require skill, but one is straightforward....the destination is all that matters. For the other, how the destination is reached is just as or probably more important than the destination.