The term “self-improvement” broadly refers to the act of improving yourself, but it can also be applied to a number of different topics. Self-improvement can include personal development in terms of leadership skills, goal setting, visualization skills, organizational skills, time management, and mind power.
That's what google says self-improvement is. Taking that, we can only edit the tag wiki to something like:
Questions about improving your interpersonal skills.
Since this is pretty useless, I'd say burn it.
Because questions about self-improvement with regard to the other topics mentioned in the google definition are off-topic here. And if people ask questions here about their Interpersonal skills, it is sort of implied they are looking to improve themselves, that they are looking for personal development in terms of interpersonal skills.
See also this meta:
When to burninate.
There are currently 8 questions tagged self-improvement. That's pretty easy to clean up.
I think this tag meets the criteria to be 'burninated'.
I think we can qualify this as a meta-tag, for the reasons described above.
Quote from the link:
The reason meta-tags are a problem is that they do not describe the content of the question. They describe some other aspect of the question, like the author’s skill level, or the author’s motivation for asking it, or generally what “kind” of question it is
In my opinion, self-improvement describes a reason for asking it, not the question itself.
It leads to off-topic questions. 4 out of 8 questions tagged self improvement are on-hold. Self-improvement has a really broad definition (see the google definition at the start of this answer). I think most of it isn't on-topic for this site, and thus the tag is only causing confusion by existing.
A self-improvement tag doesn't add any meaningful information to a question if we work from the assumption that an IPS question is asked to self-improve the OP's interpersonal skills.
There is some more advice in that burninate meta:
start by removing the bad questions it collected: find closed questions and delete them, find downvoted questions and close them (if they warrant it), find poorly-written questions and re-write them (if they deserve it). You get the idea.
So, I've cast delete votes on the 3 closed questions.
The 4 questions that are still open can exists perfectly fine without the self-improvement tag. There's 1 question that was very recently put on hold, on which I can't cast a delete vote yet.