These are some of our top tags which look like they need more/better guidance in the tag wiki excerpt:
OK - my information is definitely out of date in that case.
The theory was that tag wikis would be pushed out, but as pointed out in this answer on MSO
sometimes the tag wikis we float to the child metas do not properly fit the community.
I can only blame old age for forgetting about this.
Please suggest the edits again and I'll accept them.
Altered sounds like there is a certain ownership to it. Anyone with editing privileges can take part in shaping up a tag wiki. So the correct question to ask the community and your fellow users is whether tag usage should be included in the tag wiki.
There are a handful of redundant phrases - including some containing the name of the tag itself - that are not displayed on tags list, to help ensure there's room for the non-redundant parts of the tag excerpt.
The google spreadsheets tag wiki doesn't match any of these, so it's displayed in full.
For details, see: New tags page mangles tag wiki excerpts