The data highlighter now has a way to tag your pages manually and create a “set” for Google to understand them all most of them without having to make edits to your Zen Cart. While I am certain the site edits are more effective, I actually recommend you do both. My reasoning is quite simple, number 1 if you have any errors they will become apparent during the tagging process…. and number 2, more is better =)
Google has known searchers do this for sometime…and they have preached the use of great and unique descriptions along the same line. Remember, your Meta description does not help you rank… but is rather a unique opportunity to elicit a click from searchers. This element however, if not appropriate for the query will be replaced by a snippet to better serve the searcher…. All good, no arguments here.