Guideline for on Page Text and Boilerplate

How much text is enough on page?

[CainIV]

A question I have been asking myself lately in regards to one website I have is how much text is needed on a page to show Google that the page is unique? I know this is bit of a loaded question as it is slightly different for each site.

In my case, I use CMS on the particular site, and the Meta description uses the on page text that is unique for the page. However, the whole thing is somewhat 'boilerplate' as the titles are quite similar.