apply_filters ( 'jetpack_open_graph_fallback_description', string $var, object $data )

Notes

When a post doesn’t include any excerpt (either because you didn’t add any text in the post content, or it’s a password-protected post), Jetpack creates a default Open Graph description value, “Visit the post for more”. That description is used on places like Facebook, when sharing a link to your post.

The `jetpack_open_graph_fallback_description` filter allows you to change that value, like so:

function jeherve_custom_og_desc_fallback( $var, $data ) {
    return 'You should really click to find out more about this post!';
}
add_filter( 'jetpack_open_graph_fallback_description', 'jeherve_custom_og_desc_fallback', 10, 2 );