Two Pass Review

Two-Pass Review

A reusable review protocol that produces high-confidence findings on code changes by running a code-reviewer pass followed by an adversarial verifier pass. All output conforms to the [Output Schema](#output-schema) below.

When to use

For code review where you'd present findings to the user and a false positive costs real time (final review of a completed change, pre-merge audit). Don't present unverified findings for non-trivial code reviews — always run both passes.

For non-code artifacts (PRDs, plans, prose), spawn reviewer directly — this skill is hard-wired to code-reviewer for Pass 1.

Protocol

Pass 1 — Review

Spawn the code-reviewer agent with:

• Artifact: the file(s) or diff to review
• Criteria: what to review against
• Scope: what's in-bounds
• Output contract: "Return a ReviewOutput envelope (see [Output Schema](#output-schema)). Set verdict and evidence to null on all findings. Populate checks_run with what you evaluated (e.g., criteria names, file paths checked)."

Collect its output (ReviewOutput with P0-P3 findings + checks_run).

Auto-progression:

• Zero P0/P1 findings → terminate after Pass 1 and present the clean result in this shape:

``` Review result — clean:

• Checks run: [criterion / file path checked, one per line]
• P0/P1 findings: none

```

• One or more P0/P1 findings → proceed automatically to Pass 2. No user prompt.

Pass 2 — Verify

Spawn the verifier agent with:

• Artifact: same as Pass 1
• Findings: the reviewer's full output (Finding array)
• Criteria: same as Pass 1
• Output contract: "For each finding, set verdict to confirmed/demoted/rejected and provide evidence. Severity may be adjusted up under confirmed or down under demoted. Return a ReviewOutput envelope with the full findings array (verdicts populated). Add any new observations as new findings with their own IDs (continuing the sequence) — but first check whether the observation is a re-discovery of an existing finding; if so, modify the existing finding instead of appending. Populate checks_run."

Collect its output (ReviewOutput with verdicts + new observations).

Present to user

Report in this shape:

**Two-pass review results:**
- P0/P1 findings: [id: title — confirmed | demoted Px→Py | promoted Px→Py — evidence]
- Summary: [X] of [Y] P0/P1 confirmed, [W] demoted, [Z] rejected
- P2/P3 (FYI): [id: title — verdict]
- New observations: [id: title — severity — evidence]
- Disagreement: [none | reviewer/verifier split — sanity-check the verifier's rejections before treating as clean]

(Write None — zero P0/P1 findings after both passes when the P0/P1 list is empty.) Mark each demotion ("demoted P0 → P1") and promotion ("promoted P2 → P1") so the user sees the verifier's adjustment. All-rejected case: if the verifier rejected every reviewer finding, do not present it as clean — populate Disagreement with the rejected findings + verifier reasoning. Do NOT show rejected findings (other than the all-rejected case) or unverified P2/P3s unless the user asks.

---

Output Schema

Finding

Finding {
  id: sequential number starting from 1,
  severity: "P0" | "P1" | "P2" | "P3",
  title: short title,
  body: detailed explanation with evidence,
  file: file path or null for global issues,
  line_start: number or null,
  line_end: number or null,
  confidence: 0.0-1.0,
  criterion: what was violated,
  verdict: "confirmed" | "demoted" | "rejected" | null,
  evidence: reasoning for verdict | null
}

ReviewOutput

Findings are wrapped in a ReviewOutput envelope:

ReviewOutput {
  schema_version: "v1",
  findings: Finding[],
  checks_run: string[]
}

Severity calibration

• P0 — Must fix: breaks functionality, security breach, data loss, or violates criteria
• P1 — Fix before shipping: correct but incomplete, fragile, or reliability risk
• P2 — Should fix: quality issue, code smell, not blocking
• P3 — Nice to have: observation, style, minor improvement

Field notes

• confidence — 1.0 means certain, below 0.5 means you're guessing. Be honest.
• criterion — required for P0/P1 findings. Name the specific criterion violated.
• verdict — populated by the verifier in two-pass review. Set to null when producing findings directly.
• evidence — verifier's reasoning for the verdict. Set to null when producing findings directly.
• checks_run — list every criterion evaluated, file path checked, or acceptance criterion verified. For ACs, use AC-N: PASS — [evidence] or AC-N: FAIL — [reason].

Source & license

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

• Author: preetamnath
• Source: preetamnath/agent-skills
• License: MIT
• Homepage: https://www.preetamnath.com/blog/agent-skills

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