Second Opinion

Second Opinion

Run this on a branch that is finished and about to be pushed. It gets a second agent to review the diff, then reconciles that review against your own — so the code that ships was checked by someone other than whoever wrote it.

The reason this works is independence, not a smarter model. An agent reviewing its own work reads what it meant, not what it wrote, and goes easy on output it recognizes as its own. A reviewer with a fresh context — and, better still, a different model family — doesn't share those blind spots. So the benefit comes in two tiers:

• Floor: any reviewer running in a fresh context, even the same tool you

built with, already removes most of the self-review bias.

• Upgrade: a different model family removes more, because its mistakes

aren't correlated with the ones that produced the code. If you have a second tool, use it; if you don't, the floor is still worth running.

Engineering policy — what counts as a blocker, test expectations, DRY, git hygiene — is governed by your project's conventions (e.g. your CLAUDE.md / AGENTS.md). Apply them; don't restate them here.

Steps

Do them in order. Steps 3 and 4 are deliberately independent: dispatch the reviewer, then review the diff yourself without reading its output first, so the two passes don't contaminate each other.

1. Scope the diff. Resolve the target repo (the argument if given, else the

current directory) and confirm it's a git repo. Resolve the base branch (the repo's default branch) and compute the current branch's diff against it. State in one line: repo, branch, base, and how many commits / files are ahead. Stop if there is nothing to review (zero commits ahead) or the target is the wrong repo — don't review air, and never return a false "looks good."

1. Pick the reviewer. Choose which agent runs the review. Default smart:

prefer a different model family than the one running this skill (the upgrade); if none is available, fall back to a fresh run of your own tool (the floor). Honor an explicit choice — either named for this run, or a standing default pinned in your agent's conventions file (CLAUDE.md / AGENTS.md / .cursor/rules). Say in one line which reviewer you picked and whether it's the upgrade or the floor. For the exact command per tool, and how to set a standing default, read reviewer-cli-reference.md.

1. Dispatch the review — isolated. Run the reviewer on the diff in a context

separate from your working one (a subagent if your harness supports it, else a separate process), so its raw transcript doesn't flood your session. Hand it the diff and the rubric below. Bring back a compact findings list, not the raw output.

1. Review it yourself. Before looking at the reviewer's findings, review the

same diff against the same rubric. This is your independent pass — it catches what you know from context that a cold reviewer can't (project conventions, why a change is shaped the way it is), and it is what turns Step 5 into a cross-check instead of blind trust.

1. Reconcile and tag. Merge the two lists, de-duplicated, and tag each

finding:

• agreed — both passes flagged it. Highest confidence; treat as real.
• reviewer-only — only the second agent flagged it. This is the payoff of

a fresh / different reviewer; scrutinize it, don't wave it through or off.

• mine-only — only your pass flagged it, usually the context-dependent

ones.

On a severity disagreement, take the higher of the two. A reviewer-only finding you can't reproduce or justify is a candidate to drop — say so, with the reason, rather than importing it blindly.

1. Verdict. Present the findings by severity, then give one call: **ship /

review-needed / do-not-ship. Stop for approval before changing any code** — the skill ends at the verdict unless the user asks you to action the fixes.

Rubric

Give the reviewer, and your own pass, this bar:

• Severity: P0 blocker (correctness, security, data loss) · P1 should-fix

· P2 nit. Lead with the highest.

• Material findings only. Every finding must answer: *what breaks, why, what's

the impact, and the concrete fix.* "It could be cleaner" is not a finding.

• No findings is a valid, good result. Don't manufacture issues to look

thorough. One real blocker beats ten nits.

• Stack-specific checks — framework footguns, migration safety, query

patterns — come from your project's conventions, not this file.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: resnicdan
• Source: resnicdan/skills
• License: MIT

Install and usage instructions live in the source repository linked above.