Questions on the history of mathematics are still on-topic on this site. Thus, there is no direct need to change this (although I personally would likely not start the list with 'history', but ultimately it likely does not change much).
To answer the question on how one could change it, these descriptions can be edited directly by "trusted users" (that is, those with 20k+ points), and other users can suggest edits, which are then reviewed; for the most part it is just like for posts (only the point-thresholds are different).
To do this, one goes to the page of the tag and chooses "improve tag info" and starts editing.
For more drastic changes it can make sense to raise the issue beforehand here on meta or as an intermediate solution on chat. Likely the Tagging room is a good place to ask, maybe also CURED or even the Math Mods' Office.