That is a good extraction to take from those works.

I'd say especially in work that you can spend the time and effort, your descriptions should have a purpose beyond fodder. In terms of roleplaying, I would say that it is also true, to some extent, for roleplaying. It is easier to pull this kind of description off in writing by yourself, as you have control over the progress. Description as a means to foreshadow becomes difficult in a roleplay to pull off given the mass amount of variables.

I don't necessarily agree that there isn't a point in creating a visual aide for the reader to ensure the scene is properly set - it does create a real aspect to the scene. However, this should probably be done to a more limited basis than it now is. A lot of my friends, who 'write' (I hate to use it like this, but if you knew them you'd know why), fail to appropriately balance description for the sake of setting up a scene and description with a purpose of furthering the story or creating some element of foreshadowing. In roleplaying it is a bit different in that the balance shifts towards description for the sake of scene setting, especially so in early posts of a scene.