From https://www.mediawiki.org/wiki/Talk:Data_%26_Developer_Hub#terms
Unlike most of the linked reference sites, we don't enforce developer behaviors through a Terms of Use. To replace that, it probably will help to have a terms page somewhere mentioning licensing, rate-limiting, etc. Doesn't have to be terribly high profile or anything, but something to think about including in the design.
Currently all we really have is a single legal page on dumps.wikimedia.org, which I'm surprisingly OK with content-wise, but is pretty hard to find. @LuisVillaWMF