Links to pages do not generate OneBox rich previews

[IsaacWoods]

I tend to post each This Month in Rust OSDev to users.rust-lang.org so folks who use that and not Reddit get the chance to see it, and I've noticed it doesn't generate a rich preview (the box with the description instead of just the link).

I thought it would be enough to create the description meta tag like we do at the moment, but perhaps it needs OpenGraph tags? If someone knows more about this, it would be good if we could get this working.

[phil-opp]

I just tried a few sites on the users forum and it seems like the preview box only appears for a few well-known sites, e.g. reddit, wikipedia, etc. Other sites seem to be shown as a simple link only.