I think this is a good idea.
At the moment the "description" property is used only for room descriptions, and Harold here isn't a room, so his description property is never used (you can give him a "look" property to describe him when the player looks at him of course). I quite like the idea of the room description adding the description property of objects in the visible scope - and it would be straightforward as part of Core.aslx.
Added to the Issue Tracker:
http://quest.codeplex.com/workitem/623