Richard,
If you haven't already, please install and enable the Open Graph - Content plugin that came with JFBConnect. That will automatically set the title, description and image for Facebook based on the article contents. The image will be the first found in the article, the description will be the first 10 words (I think) and the title will be the title. Those can all be configured as well, but that's where I'd start.
Just so you know, the current description is being taken from your meta description tag, which is a generic site wide description. I'd honestly recommend looking into creating a better meta description for your pages since that's what's used in search engine results, so if you can make that more specific to your articles, that will help. That's outside of JFBConnect though, just something I noticed.
Hope that helps,
Alex