There's alot of places where if you don't know where to go, regardless of whether or not you need to open a **** or a #### that isn't obvious and doesn't respond to "open d" or "open n" etc. then you want to have on room descriptions. The most simple example would be the North Road. Unless you want to "l n;l e;l s;l w" every step, you might as well just leave brief off. This will save you life, time, and effort in many scenarios.

Oh and, if you should ever walk into one of Nepenthe's areas, I hear he gets really frustrated when people go in with brief on. And he's a deadly dragon now...ZAP.