The suggestion is to add, after each interwiki link, the number of sections that contains the linked page.
I'm on the French Wiktionary, on the page "pain". There are several links to different languages because this page exists in a lot of Wiktionaries.
On English Wiktionary, the page contains 11 sections, definitions and different languages. (equivalent to Senses in the future data model)
On the German Wiktionary, only 2.
Then, on the French Wiktionary page "pain", the interwiki links display the number of sections after the name of the language :
Use case : this inform the user how completed are the pages in the other languages, without clicking on the link. Then, this can encourage contribution, translation cross-wiki.
This feature could be considered as a gadget.