Sorry for the ambiguity, I'll add this to the FAQ.
Auto redescribe is a mode of adventuron where every time the object list or exit list changes in a room, the room description will automatically redescribe (as seen in TWO).
To enable it, add the following line to the top of your source code:
redescribe = auto_beta
It is also recommended to use the minimal TWO theme as a baseline:
start_theme = two
Chris