For best SEO results, every author page should have unique metadata. Default metadata can be set in Options > Author Features > Backup Author Meta Description. Unique language is supported through the use of the shortcode [username], which pulls in the author name.
If an author bio is available, unique metadata can be added at the author level. This information can be added within the article taxonomy in the field In Author Bio. If an on-page author bio is supported on the reader-facing frontend, this field will also be used to populate that section.
Before In Author Bio can be used as the metadata, if available, changes must be made to the Yoast settings. These settings can be changed by an administrator and may be accessed at Yoast plugin > Search Appearance > Taxonomies > Authors. In the Meta description field, the code cf_author_bio is required.