The advanced search (/search/advanced) API can search for questions by tags.

But /users/{ids}/answers API doesn't take tags.

I'd like to monitor answers/comments for questions with certain tags. Is there an API which can search for answers/comments under questions with certain tags?

If not, I'll have to use the above answers API to grab all answers within a given time range. Then check if an answer's parent question has certain tags. But it doesn't look very efficient.