It is very important to use proper self written description for posts in all sections of this site. Some sections like photo gallery, videos etc may need only 3-4 lines of description since the primary content of that page is image or video.
There should be a minimum of 25 well constructed sentences in each resource.
I think 500 words are the minimum length of an article. Because search engine only optimise larger length articles. Also, from the guide line from web master commented minimum 500 words needed in single article.