What makes a description get clicks
A good meta description tells searchers what they'll get, why your page is the right one, and what to do next, in about 120 to 155 characters. Google often shows it under your title, so it works like a small ad.
This tool reads your page (or your description of it) and writes five options with the keyword included naturally and only claims the page supports. Each one is measured in pixels so you can see whether Google will cut it off.