Help needed with Facebook and Wordpress

Hello,

I have small problem and hopefully someone here will be able to help me.
I can't figure out how to set default description and title when post from my WP site is shared on Facebook. Here's a screenshot if you someone didn't understand me:

I would like to set a default description when my post is shared on FB directly from the website. Do you have any ideas? I googled but couldn't find a solution since everything looks too complicated.
I'm using SSMAG theme and SEO by YOAST plugin if that has anything to do with this issue.
Thanks

Somebody? Anybody? Bump.

should be in the OG tag.