Who Owns What

The question that decides whether an agentic lifecycle is an asset or an incident generator isn't "how good are the agents?" It's "who owns what?" — drawn as a hard line, not a vibe.

The human side: judgment

• Set goals and priorities — what to build, what matters, what to skip. Intent is the input to everything downstream, and it cannot be delegated: an agent optimizing the wrong goal is worse than no agent.
• Approve plans — before agents burn hours of compute executing, a human confirms the plan matches the intent. Cheap to check at plan time, expensive to discover at deploy time.
• Review diffs — the working checkpoint. Not every line, necessarily — but every change passes a human gate before it ships.
• Design guardrails — the security boundaries, permission models, and budgets the agents operate inside. Humans decide what agents may do; agents decide how to do it.

The agent side: throughput

• Write the code — implementation is now the cheap part
• Run and repair tests — not just execute the suite: fix the broken test, rerun, iterate until green
• Triage incidents — classify, correlate, roll back, open the ticket, page only when a human is genuinely needed
• Generate docs inline — the change and its documentation are the same unit of work

The division follows one rule: anything with consequences gets a human owner; anything with volume gets an agent. Judgment is scarce and doesn't scale; throughput is exactly what scales. Aim each at what it's for.

In the wild

You can read this table straight off real tooling. Claude Code's permission prompts and plan mode are "approve plans" in miniature. GitHub's required-review branch protection is "review diffs" enforced structurally. Agent budget caps and allowlisted tools are "design guardrails." None of these are new inventions — they're existing controls, repositioned as the human half of an agentic lifecycle.

A table isn't a building

This settles responsibility — but responsibility isn't architecture. Where do the agents actually work? How does a plan physically become a diff, a diff become a deploy? And what makes the human gate a wall in the path rather than a suggestion? For that, you need to walk the floor.