Analysing the data for a few large sites quickly showed that descriptions of 49 characters or less are included in the report.
So what is the impact of having a ‘short’ meta description?
On the main HTML Suggestions screen it says…
These issues won’t prevent your site from appearing in Google search results, but addressing them may help your site’s user experience and performance.
…which sounds like it could be important.
However the wording above the short meta description report says…
Meta description information can give users a clear idea of your site’s content and encourage users to click on your site in the search results pages.
…which is a bit more vague and doesn’t suggest this specific issue will affect performance.
On the title tag reports the wording is much stronger…
We recommend reviewing the list and updating the title tags wherever possible.
We checked the ranking performance for a few pages with short descriptions and there were no obvious issues. Google simply used the short description and appended snippets to make up a full description. This analysis was only really a spot check and not a detailed study.
It’s logical to assume that Google’s decision to set the alert level at 50 characters and to add snippets to short descriptions is based on their own extensive analysis of user behaviour. Although they are probably not including it as part of their ranking algorithm, they appear to be suggesting their is a benefit in a more detailed description.
Despite a lack of any evidence to suggest short descriptions negatively affect ranking performance it makes sense to avoid them because of the assumed benefits in terms of click-through-rate from a controlled description.
We’ll be adding our own Short Descriptions report to DeepCrawl, our site architecture management tool, in the next release.