Meta descriptions don’t have a direct influence on your search engine rankings, but they do have a significant impact on the click-through rate.
To ensure that users improve the quality of their meta descriptions, Google released a few recommendations on how to create better meta descriptions. Furthermore, they also released an update on how meta descriptions are rendered.
How Google Generates Meta Descriptions
Historically, when a meta description for a page was missing, Google would pull out a snippet of the search result from the content itself and extract the most relevant information. However, there are times when the content itself isn’t the best source for a snippet.
In such cases, Google would extract snippets from DMOZ, also known as The Open Directory Project. For over 10 years, Google relied on DMOZ for snippets because the quality of the DMOZ snippets were often much better than those provided by the site owners in their meta descriptions.
Since DMOZ closed on March 17 2017, Google no longer uses its listing for their search result snippets. As such, it’s now more important than ever for site owners to write meta descriptions that accurately describe the content on their site.
What Makes a Good Meta Description
Google describes good meta descriptions as follows:
Good meta descriptions are short blurbs that describe accurately the content of the page. They are like a pitch that convince the user that the page is exactly what they’re looking for.
Google says that a common problem they face with meta descriptions is that site owners leave them completely empty. The other problem is the issue of duplicate meta descriptions and spammy or low-quality meta descriptions. Since these issues tarnish user experience, Google prefers to ignore such meta descriptions completely.
Google says there is technically no character limit to meta descriptions, but they will be truncated to fit the width of the device they’re being viewed on.
With DMOZ closed, Google also announced that the NOODP robots directive no longer needs to be used.
If you’d like to prevent Google from using your page contents as snippet, then you’ll need to use the “nosnippet” robots directive.
You can read more on these recommendations at Google Webmaster Central Blog.