Do you know that you can see how relevant your website’s metas are? Just check it at whois.sc/yourdomain.com

Note the 3-4th row, where is written
Seo Score and Meta Relevance.

I don’t know whether their algorithm match with the Google’s and Yahoo ones, but that should be easy handy tool to verify your websites metas quality. As for my opinion, description and keywords tags are not so important as Title tag. You may noticed high ranking sites over the net, without description and keyword tags. This is the fact that the 1st considiration of the site depend on title, rather than other meta tags.