> The idea is to create a markdown file where an AI agent is asked to work as a QA engineer

Given your code-base is mature enough, please don't have a single Skill/Steering/Persona/Ruleset (or whatever) for your "QA Engineer." This is just the same "my behavioral file can one-shot the entire system build" kind of thinking that will give you expensive, marginal results as the system grows.

If you want to have success in this space, get really fine-grained. Every single test scope needs its own behavioral files.

Have your core behavioral file define some simple specifics around Test Pyramid, Test Purposes, checks for tautological tests, etc. Then get _really_ specific;

<test-type>-architect (plan)

<test-type>-engineer (execute)

<test-type>-resolver (problem solver, maintenance, how to manage a failure, etc.)

e.g., playwright-architect, etc.

Then create additional ones for Unit tests, API tests, contract tests, or any other required test layer for the SUT.

Overengineered? Maybe given the size of your codebase. But for anything significant, you are codifying what humans and their skillsets do.

[dead]