So you're fine with your code having unintended behaviour, as long as that unintended behaviour passes a test that the agent wrote?
My preferred approach is to read and understand everything the LLM produces AND have it create test suites (which I also read and understand). The LLM can help you with that too - just have it breakdown and explain the code at each iteration.
If it's code for a pacemaker, it should be reviewed by multiple humans. If it's code for an unimportant side project, I will never read it. Between those extremes are shades of grey.
Part of our job in this new era is to understand the worst-case consequences of a bug given how the code interacts with the world, then allocate our effort based on that understanding. This can only be done on a case by case basis.
My preferred approach is to read and understand everything the LLM produces AND have it create test suites (which I also read and understand). The LLM can help you with that too - just have it breakdown and explain the code at each iteration.