I think I am missing something. At 1500 reputation a user qualifies to edit Tag Wikis. Is this the same as the tag descriptive text found under 'more info' ?
I looked at the description of a tag wiki and found this
Tag wikis are a general introduction to a topic defined by that tag. They're a place to consolidate and form a sub-community around a tag. They contain, among other things, frequently asked questions in the tag, top users in the tag, and best recent answers in the tag.
I have not seen anything on this site that appears to actively do this. Earlier I wrote an extension to the tag 'design' which was discussed in meta on this question: (Appropriate use of tag wikis). At the time I thought I had misinterpreted the intent of tags, but after reading this, I am a bit confused.