Using Webmaster Tools to Make Fundamental HTML Improvements
The most powerful weapon in your digital fight to top the search results at Google is Webmaster Tools, as the platform provides a great deal of insights into your current performance and where there is room for improvement.
One of the easiest ways to take advantage of the system is to dive in to the HTML Improvements section within the Site Appearance category (available under the Site Dashboard).
What is important for webmasters about this section in Webmaster Tools is that it reveals issues related to meta descriptions and title tags. The system flags pages that essentially need to be fixed; pages that don't conform to the now well-established best practices related to title tags and meta descriptions (ensuring they are informative, that they meet the optimal length requirements, and are unique to the page they are located upon).
Webmaster Tools shows pages with duplicate meta descriptions, as well as meta descriptions that are considered too long or too short: in the case of a meta description being too long, it runs the risk of being truncated (and confusing to the user), whereas a meta description that is too short risks not being informative enough to capture the attention of the search engine user.
The duplicate meta description report should definitely be the focus of those using Webmaster Tools as too large a percentage of pages (based on the total number of pages) can signify a "foundational" problem with your website which correcting could result in greater visibility on the search engines. In the screenshot below, for example, the duplicate meta descriptions signified that content published in one location but grouped in different interest categories were being indexed by Google with the exact same description (which could be a problem). The quick fix would be to change the meta descriptions, but a longer term/permanent fix would be to modify the CMS setting to change the meta description when republished (or not republish it twice on the same site).