Google and other search engines work with the meta tag description to allow webmaster to detail which text to appear in the search results pages of search engines. But Facebook works with some other specific tags to perform the same function. If we do not use these specific tags it is possible that when posting a link in your profile or facebook page you will find that there is an incorrect description.
The solution is very easy, using a specific tag such as
Additionally, there are more tags to be used in Facebook, we can detail other parameters when we share a link such as the image that appears with the link, title, etc.
A common problem is that despite these metatags have been incorporated into your website, you can continue seeing the ancient description. That means that your page is in the cache of facebook and you have to delete it. Simply go to Facebook debugger and introduce your website, it will remove the cache of Facebook and publish information containing your metatags.