Filling In The "Description" area of web directory submission form

Just curious about how directory owners see this or prefer it. Most forms are 500 words/characters max. Some are less. Bust overall, my descriptions run around a paragraph.
Is a paragraph about average? I try to infuse a couple of choice keywords into that desciption of course, but am curious as to whether it is best to use as much wording or basically a descriptive paragraph with a couple of good related keywords to the URL you're submitting? Or (get this) leave it BLANK? What happens in that instance?

 

personally, a nice short description with appropriate keywords is sufficient.
IMO leaving the description area blank is a mistake, otherwise your relying totally on the website name as a draw.