A way for tag short descriptions to be presented/viewable in both the autocomplete/tag suggestion dropdown, and the tag editing UI itself. Tag short descriptions currently pop up as a tooltip if you mouse over a tag's link _*when it's on an image_*, but not in the autocomplete/suggest dropdown nor while they're in the fancy tag editor.
Rationale: the tag short descriptions often contain notes and hints about how certain unintuitive tags should be used (for example, "[neon lights":](/tags/neon+lights)) so it would be directly useful for them to appear where you do tagging.