The only one of those that has any value with regard to SERP is the
description. You can ignore all the others except for the revisits and
robots ones which may be useful in guiding the search engine spiders on how
to index your site.

The remainder as strictly used for special purpose needs. You can find a
complete description of them all here -

http://en.wikipedia.org/wiki/Meta_ta...ords_attribute

--
Murray