I've been looking into similar ideas but more aimed towards backend-specific testing. Have you explored this area at all, or is agent-qa frontend tests only?
But the issue with API testing / backend is that coding harnesses are really good at it. A product manager who writes user stories should be able to write tests for the product, and usually PMs don't care about the APIs.
Do give agent-qa a try, and consider giving it a star on GH https://github.com/vostride/agent-qa
Thanks!