rpmlint very anally tries to force people to create lines of 79 columns max in descriptions. No 79-column terminal was ever shipped. That means what rpmlint asks is incompatible with the defaults of common tools such as fold. If the intent is to leave some margin, usual mail margin is 72 column not 79. In other words rpmlint does not make any sense nor follows any common convention which is wasting the time of everyone involved (not to mention no one is actually limited to 80×25 terminals nowadays) Please fix to at least standard 80 column width. rpmlint-0.81-1.fc8.noarch
Some editors wrap 80-column lines so that the 80th char is wrapped to the next line in their default settings. Some others and especially terminals make it difficult to see whether the line following a 80 char one is attached to the 80 char one or a new line. Even though the issue is a very cosmetic one considering %description and Summary, as far as I'm concerned, 80 as the max line length is a no go, but I wouldn't mind 72. But because it's a matter of taste, I'm not inclined to make any changes to this without a public mailing list discussion that reaches some kind of a conclusion -> WONTFIX. If such a discussion and conclusion takes place, feel free to reopen and I'll make changes accordingly.
you may be interested in bug #521630 which may fix you issue - but if you insist on changing the default, just initiate the discussion ...