The wiki has no such restriction..
Stick it up there, ask for comments on wiki and ooc in realm and when the timeout expires make with the cut-n-paste magic.
Though I have seen no obvious rules on the subject I tend to write non-partisan descriptions with as much colour and implied richness as can be squeezed into a couple of paragraphs. It's better for atmosphere and when your enemy steals the region they are less likely to entirely remove your carefully crafted and researched hard work. (Worth keeping in mind if you are the invading party).
The best region descriptions do not just describe geography and landmarks but describe how they affect the people and culture of the region. People are more interesting than hills and trees,