That’s effectively the same as having an incorrect/out-of-date runbook. Except the likelihood of that happening with automation is much lower if you write test

That’s effectively the same as having an incorrect/out-of-date runbook. Except the likelihood of that happening with automation is much lower if you write tests to ensure they work when deploying. There are always some break-the-glass mechanisms that should be documented (like, how to log on to a host). I’m just saying that in mission critical systems, you can dramatically reduce risk by minimizing the amount of manual work you have to do, which prevents mistakes.