They should match the pages content on an individual basis....

Don't try to use "red widgets" on a page about sausage links...there's no point...it used to work...but no longer...

Duplicate meta descriptions have recently caused Google to drop the pages from their main index. So, I would do whatever work it takes to get a unique meta description on each html document if you want that url to show up in search results.

In many cases Title+Description is what will show in the search results -- you are writing your own "ad" for the page by making these two elements refer to the unique page content.

Thanks guys, I was afraid that would be the answer,