Description meta tag missing (Yoast SEO)


Hello everyone,

I’m using Yoast SEO on Wordpress and am trying to get my Twitter Card validated (summary with large image). I have ticked the “add Twitter Card meta data” box in the plug-in, entered my username and selected the right card. Then I went to the Card Validator and only one thing is missing which is the description meta tag.

What’s confusing me is the line in the plug-in under “add Twitter Card meta data”: “Add Twitter card meta data to your site’s section.” Is this a description? An instruction? I guess the first, but correct me if I’m wrong.

Thank you in advance for your help!