Social previews6 rules onthe details your pages declare for link previews.

The title, description, image and address a share card is built from.

Open Graph

A declared sharing image needs attentionAn Open Graph image has a confirmed access problem, is small, has a relative address, or has declared dimensions that differ from its measured dimensions.In the report: A declared sharing image needs attention
An eligible page has no root og:image tagAn eligible indexable HTML 200 page with a completely captured head has no root og:image declaration; og:image:url alone does not satisfy this check.In the report: Indexable pages have no og:image
An eligible page has no share descriptionAn eligible indexable HTML 200 page with a completely captured head has no og:description declaration.In the report: Indexable pages have no og:description
An eligible page has no share titleAn eligible indexable HTML 200 page with a completely captured head has no og:title declaration.In the report: Indexable pages have no og:title
The share address differs from the canonical addressA page's one unambiguous og:url and head canonical resolve to different addresses.In the report: Pages declare an og:url different from their canonical

X cards

Review the optional Twitter Card declarationThe captured head has no explicit Card type, an empty type, or a type listed as deprecated in a historical publisher archive.In the report: Twitter Card declaration missing, empty or historically deprecated