Let me play a little bit of school on you. So, it actually turns out that we used to not use the Meta description at all. We would only use the snippet appropriate to the specific search query. And only in recent years have we added it where if you have a meta description, we will sometimes choose that meta description over a little snippet from within the page. So, in fact it’s moving the other direction. We started out as only having stuff from within the page, and now we’re a little more likely to sometimes use the meta description.
If we think it’s useful for the query, you know, don’t make the same meta description on every single page just as a cookie-cutter because then we sort of think, well that’s not a very useful meta description. So, it’s not that we’re doing away with the meta description. We use it more now than we did, say seven or eight years ago. But at the same time, we think it has to be useful before we’ll use the meta description.
And then you’re more likely to see that instead of the snippet from the page. Now, if you don’t want to bother, that’s completely fine too. We’ll just try to do whatever we think is the smartest and the best for users, and hopefully users will click through and find your content.
by Matt Cutts - Google's Head of Search Quality Team