I wouldn't worry about how many undefined tags we have - instead focus on making sure that the top-used tags* (tags covering ~90% of questions) have tag wikis (and excerpts) that are meaningful and describe not only what the tag represents, but when the tag should be used as well.
Of course, if you're in the mood and feel like creating some lesser-used tag wikis, go right ahead!
* which incidentally is how the Tags page is sorted by default
To address concerns about tag misuse:
Don't get hung up on tag definitions as a 'silver bullet' way to solve the mistagging issues. Generally, people who tag incorrectly do so because they don't bother reading the tag definition.
A current example of this is the msi tag, which the tag definition clearly stated that this was for the windows-installer filetype .msi, not for the company of the same acronym who produces computer hardware. Yet a lot of its uses were for the latter. (It was cleaned and synonymised with windows-installer in the end)
What we should be focusing on instead is reducing ambiguity in our tags. Ambiguous tags lead to tag misuse - even with a tag definition.
We can do this by:
- Using full names in our tags (where possible)
- Avoiding acronyms or shortened names.
- Avoiding tags with multiple meanings
- For example: Instead of tagging with command-line, we should tag with the specific terminal-program (powershell, bash, windows-command-prompt etc)
- Being explicit in the wording of our tags
- e.g. Instead of just power, we should use power-supply
- Instead of vlc, we should use vlc-media-player
- Removing obvious meta-tags.
- These are tags that are subjective, like 'beginner' (beginner according to what criteria?), and describe the person or the question, not the problem/topic at hand.
