Meta descriptions are a succinct synopsis of the content on a web page. They are commonly used on SERPs as a preview of any given page displayed by a search engine. They average around 155 characters.
These descriptive tags are not an integral part of an SEO setup, but they are very important to user experience. They help drive click-through rates from SERPs. They give users an idea of what is on the page prior to their clicking the link. They are short paragraphs that preview the content on a site to give searchers an opportunity to know exactly what content is on the page and if it is the information they are looking for in their search. A Meta description uses keywords to create an informative and compelling explanation of what is on the site. The ideal Meta description should have express relevance to the specific content on the page. This should all be done with the parameters of 150-160 characters.
<meta name="description" content="This is an example of a meta description. This will often show up in search results.">
Optimal Length for Search Engines is roughly 155 Characters
In many ways, a Meta description serves as a means of advertising for the link. Readers can be drawn into reading the content and visiting the website from the summary provided in the SERP. This is an important part of search engine marketing. Creating easily read engaging copy that utilizes keywords can provide higher click-through rates. Maximizing click-through rates requires utilizing keywords and descriptions to highlight the content on the website being marketed.
It is true that you can put as much information as you want into a meta description, only the first 160 characters will show up in the SERP listing. To prevent your descriptions from being truncated it is best to keep all descriptions around 155 characters.
It is important that each page on a website have its unique meta description. This is an example of having duplicate meta titles and descriptions
Google does not use meta descriptions or meta keywords to rank web pages. Meta descriptions are used by Google only as a means of providing a content preview for users.
Non-alphanumeric descriptions will cause Google to cut off the description. Anytime a quote shows up in a meta description it will be removed and eliminated. The only way to prevent this deletion, single quotes needs to be changed to double quotes.
It would seem that adding a meta description is always preferable to not adding one. This is not always true. If a page is targeting between one to three search terms or phrases, the meta description should be used to target the users searching for those keywords.
If a page is targeting three or more keywords or long-tail traffic, it is preferable to let the search engine generate the content. This works because search engines pull the display keywords and the phrases the user would have searched for in the initial query. If a description is forced onto a meta tag that is not as relevant as the one that the search engine could have created it ends up being less effective as a marketing tool.
Not adding a meta description can be a gamble. There are cases where the search engine overrules the meta description in favor of one it generates that is more in line with the queries. It also bears mentioning that social media sites will not add meta descriptions and it will grab the first lines of content to fill the void.