You can display the room's description by printing its "look" property. For example:
msg <#(quest.currentroom):look#>
(In QDK, put #(quest.currentroom):look# in the parameter for the print command).
You can run scripts when a room description is displayed anyway. Just specify your own description script. You can do this at game level, by putting a "description" tag in the "define game" block (or by putting the script in the Game Properties window in QDK), or you can do it at room level.
You can clear the screen when a player enters a room by putting the clear command in a "script" tag for the room. Again this is easily done in QDK.