[Plugin: All in One SEO Pack] What to do with individual-post fields?

Well, should I fill them in or leave blank? There’s already tags field and title field when creating a post. Or should I fill both the “regular” fields AND the plugin’s fields for title and tags? As far, as I know, the description is taken as beginning of the post if left blank, so if I want that as a description anyway, I should leave it clean I believe.

https://www.ads-software.com/extend/plugins/all-in-one-seo-pack/