How longdescs are used for mobs (and for PCs) in some dikus:
look west
>The green-furred kobold is here, growling hungrilly.
look here
>This is the room. It has a description, around six lines long. There's mention of some
trees, a clearing to the west, undergrowth and various other vegetation, and the
sound of a bunch of different animals. Because this is a semi-dynamic room description,
you can tell it's presently daytime, since the room description talks about light filtering
in through the branches.
>A grainy red stone rolls around the ground.
>The tall, slender woman stands stiffly against a tree.
>The black-haired half-elf watches the west, arrow poised against his bow.
In the examples above, the kobold is an NPC. The tall, slender woman is a PC, who is hoping the kobold doesn't see her, because if he does, he'll come in and try to kill her. The half-elf is also a PC, who is trying to protect his friend by killing the kobold from a distance.
The rough red stone is just a stone - maybe the woman dropped it, or some other guy was foraging looking for nicer things and found that and left it there. Or possibly someone tried to shoot a sling at the kobold and missed
If I were a hunter passing through, these are what I would see, when I walk into the room, or type "look here" and when I type "look west."
As a player, I would be able to set that long description, OR I could let the game keep the default: %N is standing here. Or %N is sitting here, looking exhausted. Or %N is asleep here, bleeding profusely. However is appropriate for the situation. Different coded criteria return different ldescs. The generic default would be "%N is standing here."