Since the tag derivations has no usage guidance at the moment, I do not know when it should be used, which is unfortunate.
I think that indeed:
in analytic questions about specific derivatives/ differentiation, the tag should be removed (it is then not very relevant: if it were, it would be relevant for thousands of questions). When necessary, it could be replaced by better tags (e.g. real-analysis, ca.classical-analysis-and-odes, dg.differential-geometry, differential-operators... maybe also differential-calculus although the latter doesn't sound like a research-level tag).
tag info should be added, indicating that this concerns derivations in a (kind of) algebraic setting.
Another possibility is removing the tag altogether. Let us consider the pros and cons:
I can easily see people repeating the same mistake and misusing the tag, even with better usage guidance. So keeping the tag tidy will require further effort.
There seem to be only few questions that would keep the tag after the retagging YCor proposes, and it seems to me that they all contain the word "derivation" in the title. So it will be simple to search for questions on derivations even without the tag.