5:55 AM
"editing and improving tag-infos should certainly be encouraged. However, it seems that not many users of this site find the time to do this". I don't think it's a matter of time. Indeed, the site's feature for this are very poor, at least to my understanding. Edits would typically require discussion, and a discussion is not really possible, except specifically posting on meta for this, which is not practical, and discouraging for minor issues. — YCor 1 hour ago
I certainly agree that in the times when quid and Ricardo Andrade were active on this site, there was more discussion about tags. (Many of the recent posts about tags on meta received basically no feedback.)
Although recently S. Carnahan edited several tag-wikis, Todd Trimble mentioned here in chat that he would like to get more involved in tag-related issues, and François G. Dorais created a few tag-infos (and interacted with some tag-related posts on meta) just a few days ago.
So it's possible that some moderators have a bit of interest in tags.
However, François G. Dorais confirms here that there is not much discussion about tags on this site now:
Oct 16 '17 at 4:07, by François G. Dorais
In the early days of MO, there was a lot of tagging discussion which helped draw guidelines for what other tags might be useful and appropriate for the site. These days, however, only a handful of users are interested in tagging issues, probably since the system works well enough for everyone.
Also quid's here (and in a few messages before and after) compares the tag systems on the two sites (Mathematics and MathOverflow):
Nov 20 '15 at 18:27, by quid
Just look around: how much community moderation or maintainance do you see beyond closing? The list of users by edits shows this too http://mathoverflow.net/users?tab=Editors&filter=year It is not even possible to maintain the most elementary guide that the top-level tags should be used. To be sure, lately I do not do much about it either.
@YCor I disagree (to some extent). I think that issue which require discussion is if there is unclear (or not enough consensus) on how the tag should be used - in which case I consider the fact that usage of the tag is unclear or inconsistent a bigger problem than a missing tag-wiki. The fact that these days there is not much discussion around tags is confirmed for example in the message by François G. Dorais which I quoted in chat. (Where we can discuss this further if this is too much of a digression.) — Martin Sleziak 1 min ago
However, some edits to tag-wikis do not take so much time (at least for a user familiar with the area and in cases where the usage of the tag is clear). For example, adding a link to great resource you know does not take much time (in some cases even a post on MathOverflow might be suitable - especially if there is a post collecting good materials for given area). — Martin Sleziak 51 secs ago
Another example of an edit which does not take much time is adding some basic links (such as Wikipedia or nLab) - both to have some resources and also to help with the tag-infos which were simply copied here without proper attribution. Such problem was previously mentioned here on meta in these posts: Recent suggested tag wiki edits and Should tag-wiki include a source where it is taken from?Martin Sleziak 51 secs ago
Having said that, I should also say that many users here help with retagging incorrectly tagged questions. (Still, it would be nice if there were more of them.)
Some such users were mentioned here:

### MO users active in retagging

Oct 24 '17 at 11:35, 3 days total – 68 messages, 3 users, 0 stars

Bookmarked Oct 12 '18 at 16:07 by Martin Sleziak

Some users which I have noticed doing some tag-related edits: YCor, GH from MO, S. Carnahan, András Bátkai, Rodrigo de Azevedo, Ben Barber, David Roberts, François G. Dorais, Yemon Choi, Willie Wong, Joel Reyes Noche, j.c., Paul Plummer, Arun Debray, darij grinberg. And probably many others who I did not notice.
You can find some tag-related edits if you look at edit summaries containing some keywords specific to tags, such as level or deprecated.
Searching for "tags" in edit summaries will probably return too many edits, so here is a query for such edits all time and in 2018.
However, if we want all tag edits, it is easier to use PostHistoryTypeId=6.
Here is the list from 2018, of course the dates can be easily changed - here is the same query for 2010.
If there is interest in such statistics, it should not be too difficult to count how many times which username appears in the queries above. (And perhaps they should be also modified to include not just UserId but also UserDisplayName - which is shown for deleted users.)

2 hours later…
8:20 AM
@MartinSleziak Now there are two questions with the tag - so if they both stay on the site, the tag will be immune to roomba.
6

Let $n\ge 1$ be an integer and let us work over the field of complex numbers. Let $\mathcal{R}_n$ denote the set of rational conic bundles $\pi\colon X\to \mathbb{P}^n$ (morphisms such that the generic fibre is a geometry irreducible conic and $X$ is rational), up to square equivalence: two conic...

1

Consider the quadratic forms $$Q_1 = x^2 + y^2 - (t^2+1)z^2,\qquad Q_2 = x^2 + y^2 - z^2$$ over the rational function field $\mathbb{F}_p(t)$, where $p > 2$ is a prime such that $t^2 + 1$ is irreducible over $\mathbb{F}_p$, i.e., $p \equiv 3 \ (\mathrm{mod} \ 4)$. These forms are isomorphic ov...

5 hours later…
1:38 PM
I agree that edits without discussion are easy to do, under, however, the restriction of having the right to edit a given tag, which requires to have a certain number points gained on question with this tag (I was once blocked for such a reason). Another illustration of the awkward situation about tagging is the artificial embedding of "Help cleanup tags" as a multi-answer question, in which the settled cases are deleted. — YCor 21 mins ago
@YCor You don't need to have any score to be able to edit the tag-wiki, the only restriction is that under 20k any edit to a tag-wiki needs to go through the review. You probably mean tag synonyms - that is where you need score +5 to be able to suggest a synonym. — Martin Sleziak 13 mins ago
Regarding the "Help cleanup tags!" - this was the decision made by the creator of the thread - which was François G. Dorais. Personally, option to have single thread seems reasonable to me, some issues are too minor to guarantee a separate question - but I might be wrong. I have mentioned a few times that I dislike the fact that the mods delete closed discussions in those thread - again other users might have different opinion than I do. — Martin Sleziak 13 mins ago
I'm fine with this "Help cleanup tags" thread, it's just the less bad option according to what is currently technically possible. Clearly it's not a natural one. — YCor 10 mins ago

3 hours later…
4:20 PM
The question Number of Lyndon words only has one small tag - no top-level tags, not tags that have watchers/followers. Which tags would fit there? Perhaps and ?
0

1) In the following OEIS Sequence, what is the meaning of One alphabet labeled, the other $3$ unlabeled? The number of Lyndon words (aperiodic necklaces) with $4n$ beads of $4$ colors, $n$ beads of each color. One color labeled, the other $3$ unlabeled. \$1, 52, 5133, 656880, 97772875, 1603...

1 hour later…
5:42 PM
@MartinSleziak That question is deleted at the moment.

1 hour later…
6:52 PM
0

There are 7 occurrences of lmis, whose tag info is "Linear Matrix Inequalities (LMIs)". I suggest to replace this tag with non-existing linear-matrix-inequalities since tags are usually not abbreviations.

As usually, I will add link to SEDE query listing past occurrences of the tag (which shows 7 questions): data.stackexchange.com/mathoverflow/query/927958/… And to deleted questions - at the moment there is 17 of them: data.stackexchange.com/math/query/883845/…

1 hour later…
8:16 PM
@MartinSleziak I waited a bit to see whether I get some feedback here in chat. Then I simply edited the question to remove the deprecated tag.