Same agent, same prompt, different runs. Which output do you ship?

I've been running the same task through the same Claude Code instance across several sessions this week. Different days, different context states. The outputs are meaningfully different. Not wrong vs. right. More like: one pass took careful, incremental steps with explicit file checks before each write. Another went faster, made assumptions, and produced code that worked but had three undocumented behaviors. Both cleared CI. The problem isn't that one was bad. The problem is I have no principled way to choose which one to ship. I'm doing it by feel: the pass that "looks more careful." That is not a system. We have solid tooling for evaluating outputs: tests, linters, code review. We have basically nothing for evaluating the decision pattern an agent used to get there. Two different behavioral profiles, same output shape, no way to distinguish them without replaying the session manually. Not asking about eval benchmarks or leaderboard scores. Those are population-level signals. I mean per-instance, per-run variance: does this specific agent instance, in this specific codebase context, tend to make the kind of decisions I can sign off on? Curious what patterns people have found that persist beyond a single session.