tedster - 3:38 pm on Aug 28, 2012 (gmt 0)
It's fine to link to Google Help Pages. You may be referring to this page, which I think is a pretty thorough introduction: One source of information is here: Site title and description [support.google.com]
One goal of a snippet (and title) is to get a good click through ratio when your URL does get an impression in the search results. One challenge is that a given URL sometimes appears for more than one query phrase, and this means one description may not work well as a snippet in each situation.
This is partly why Google reserves the right to create their own snippet for some search results, even when the site offers its own meta description.
And yet there are situations where generating any meta description at all may not be practical. This used to mean seeing a description snippet that read like a pasted-together ransom note. Today, it's not usually that bad and Google's automated description snippet can work out pretty well.
So I don't think there's any single answer for all low text content pages. If the number of pages is manageable, you can take your best guess and then see whether you get clicks when you rank. For large sites, it's usually not practical to review everything and duplicating page content may be the best you can do, especially if you need to automate the process. But even then, you can still cherry-pick the URLs that get the most search traffic and given them some one-on-one attention.