(to a client, part of a long e-mail on doing their site. They had written that SEO would be easy because we could just grab the meta tags from the old site.)
A note on SEO:
Meta tags are, by and large, irrelevant to modern search engine results because they were abused so much in the past. The description meta tag, though, is quite important not for ranking, but because Google uses it as the text below the link that people can read before deciding to click through to your site or not.