They do read the meta description tag for sure. Ive seen it used for the SERP description many of times. Also a unique title and description for every page helps out with supplemental results.
Meta tags are used to add information to the HTTP header of a webpage. It also contains hidden information in the coding that the search engines will pick up on. Example: author's name, title of web site and "keywords" Meta tags can help improve your placement in search engines and can therefore help increase traffic to your Web site. Most likely, if your site does not have "keywords" in the head of your html code, the engines will not find your website Choosing your keywords carefully: Choosing the keywords used in your meta tags are very important. If you don't choose the proper keywords, submitting your site to the search engines will be useless, because those keywords are major factors in determining how a site visitor will locate your site in the engines.
As Aaron wrote, not only it's important, but if you could make meta tags for each specific pages, you're on your way...