Adding Meta-Description to CSS Manager

Howdy.

I would like to add a meta-description to my blog, http://www.therightcardandmore.com

I understand from reading the Codex that I can use this template to do so:

<meta name=”description” content=”Special stories and
tales about dogs, cats, birds, ferrets, and other
domestic animals as told by Harriet Smith,
veterinarian. Stories include tales of animal
bravery and courage, life and death, companionship,
and the wonderful joy animals and pets bring to
their human partners.” />

My question is, after I make the changes I need to make to the template, making the content specific to my blog, can I then paste it into the CSS Manager or would I be better off copying it into a Yoast SEO field?

Thank You!