adversarial-review-change

name	adversarial-review-change
description	Change-mode review procedure for the adversarial-reviewer agent. Fires when the target is a code diff, GitHub PR URL, or working-tree diff. Invoked by the agent's turn-1 dispatch.

Adversarial Review — Change Mode

You were dispatched here by the agent's turn-1 mode dispatch because the target is a code diff, PR URL, or working-tree. This skill defines the full pipeline. Execute it without deviation.

Vocabulary, constants, evidence labels, verdict scale, and pushback protocol are defined in ~/.pi/agent/agents/adversarial-reviewer.md. Do not redefine them here — use them exactly as specified there.

Artifact Sections 4 (Citation Shepardizing) and 7 (ACH — Competing Hypotheses) are research-mode-only — change-mode artifacts omit them entirely. (These are output-artifact section numbers, distinct from pipeline steps S4/S7 below.)

---

Input Acquisition (Execute Before S1)

Determine what diff to work from. Exactly one of these applies:

Target type	How to acquire
Working-tree diff vs. base ref	git diff <base>...HEAD (default base: main); if no base supplied, use git diff main...HEAD
GitHub PR URL	gh pr diff <PR-URL> — fetches the full unified diff
Explicit .diff / .patch file path	read the file directly

After acquiring the diff, also read --context <path>... files if the flag was supplied. These are non-diff files (e.g., related modules, interface definitions, docs) provided for grounding.

Context starvation rule (critical): Diffs strip surrounding functions. Objecting against stripped context is the #1 false-positive source in change-mode. If --context files were NOT supplied, read the full surrounding functions for every changed hunk before proceeding to S2 and S4. Use read with offset/limit targeting the relevant file and line range visible in the diff headers.

---

Pipeline: S1 → S2 → [S3 optional] → S4 → S7 → S8

S1 — Restate the Change

What it produces: A plain-language summary of the change in the reviewer's own words — not a paraphrase of the commit message.

How to execute:

• State: what files are touched, what the change does functionally, what the apparent intent is
• Note what is NOT touched that you expected to be (missing migrations, missing tests, absent callers, etc.)
• Do not evaluate yet — this step is purely descriptive

Output format:

## Change Summary (S1)
<2–4 sentences: what changed, which files, apparent intent, notable omissions>

S1 informs the Bottom Line (Section 2 of the artifact) — it is not a standalone artifact section.

---

S3 — Steelman (opt-in, --steelman flag only)

Insert between S1 and S2 only when --steelman is passed.

What it produces: The strongest defensible version of this change — the argument for why it is correct, safe, and necessary.

How to execute:

• Articulate the best case for the change: what problem it solves, why this approach is reasonable, what constraints it operates under
• Do not hedge the steelman — state it confidently. This is the strongest form of the argument you're about to attack.

Output format:

## Steelman (S3)
<3–6 sentences: the best version of the argument for this change>

Steelman is not an artifact section in the final output — it is a working step that sharpens subsequent objections. Include it in the working notes but not in the final composed artifact sections.

---

S2 — Key Assumptions Check

What it produces: Surfaced implicit assumptions the change makes about surrounding code, callers, data shapes, user behavior, concurrency, and environment.

How to execute:

1. If no --context files were supplied: read the full surrounding functions for every changed hunk now (if you haven't already). Use read with file path and line range from the diff headers.
2. Identify assumptions the change makes that are not validated in the diff:
   • What does the changed code assume about its callers? (argument types, call frequency, concurrency)
   • What does it assume about data shapes? (null safety, array bounds, field presence)
   • What does it assume about environment? (env vars, file system state, external services)
   • What does it assume about user behavior? (ordering, retry logic, idempotency expectations)
3. Assign each assumption a confidence that the assumption is actually true given what you can read in the codebase. This becomes the impact-if-false column.

Output format (→ Section 5, Key Assumptions Surfaced):

| Assumption | Confidence it holds | Impact if false |
|------------|---------------------|-----------------|
| <what the change assumes> | <% range> | <what breaks> |

---

S4 — Pre-mortem: Production Incident Opener

What it produces: An unfiltered list of speculative failure modes. This is the highest-value step in change mode.

Epistemics: Pre-mortem items are hypotheses, not claims-of-fact. They do NOT require [FETCHED]/[CODEBASE] evidence labels. Inclusion criterion is looser than objections: "plausible enough to be worth defending against" — not the TIER_2_CONFIDENCE_FLOOR floor that governs objections.

Framing prompt for this step:

Assume this change shipped to production and caused an incident. Why? Generate the unfiltered list of plausible mechanisms.

Failure mode categories to sweep (do not skip):

• Null/empty/zero inputs hitting the changed code path
• Off-by-one errors in loops, indexes, ranges, pagination
• Race conditions, missing locks, double-writes, TOCTOU
• Error handling gaps — exceptions swallowed, partial failures silently succeeding
• Security holes: injection vectors (SQL, command, template), auth bypass, secret leakage, SSRF
• Performance cliffs: N+1 queries, unbounded loops, missing indexes on new queries, large payload assumptions
• Breaking API changes: callers that weren't updated, wire format changes, serialization assumptions
• Missing tests: what invariant is now unverifiable in CI?
• Dependency-introduced behavior: what does the library actually do at edge cases the author may not have checked?

Format each item as:

**PM<N>: <hypothetical incident title>**
Mechanism: <1–2 sentences — what code path fails, under what condition>
Prevention: <what code or check would have caught this>

Hard rule: Do NOT promote pre-mortem items to Tier-1 objections unless they independently meet the objection evidence + confidence bar (TIER_1_CONFIDENCE_FLOOR). Pre-mortem and Objections have different epistemic weight — gaming the system by cross-promoting defeats the purpose of keeping them separate.

Output format (→ Section 6, Pre-mortem Failure Modes):

## Pre-mortem Failure Modes (S4)

> Assume this change caused a production incident. Speculative — distinct from evidenced objections.

**PM1: <title>**
Mechanism: ...
Prevention: ...

**PM2: <title>**
...

---

S7 — Structured Objection List

What it produces: Tiered, evidenced objections per D8 intensity calibration.

How to execute:

1. For each potential objection, assign an evidence label from the taxonomy in the agent file ([CODEBASE], [FETCHED], [REASONING], [ABSENT], [TRAINING]). In change mode, [CODEBASE] dominates — include file.ts:42 plus verbatim code excerpt (within FETCHED_QUOTE_MAX_CHARS).
2. Assign a confidence range.
3. Tier the objection:
   • Confidence ≥ TIER_1_CONFIDENCE_FLOOR → Tier 1 (load-bearing; drives verdict)
   • Confidence TIER_2_CONFIDENCE_FLOOR–TIER_1_CONFIDENCE_FLOOR → Tier 2 (secondary)
   • Below TIER_2_CONFIDENCE_FLOOR → dropped; count only in footer
4. Apply the Cluster Rule: if 3+ Tier-2 objections point at the same assumption, escalate to a synthetic Tier-1.
5. Apply TIER_1_HARD_CAP: collapse by theme if you would exceed the cap.

[FETCHED] usage in change mode: Use when challenging library or framework behavior the change relies on (e.g., "this assumes Promise.all short-circuits on rejection — per MDN [FETCHED quote] it does not"). Always include verbatim quote ≤ FETCHED_QUOTE_MAX_CHARS. No quote → downgrade to [TRAINING] with confidence cap.

Output format (→ Section 3 Tier-1 + Tier-2, Section 8 Unfalsifiable):

## Tier-1 Objections (Load-Bearing)

**O1: <title>**
[CODEBASE] `src/foo.ts:42` — `<verbatim code excerpt>`
Confidence: <X%–Y%>
Consequence if true: <what breaks in production>
Detail: <reasoning>

**O2: <title>**
...

## Tier-2 Objections (Secondary Concerns)

**O<N>: <title>**
[REASONING] <explicit logic>
Confidence: <X%–Y%>
Consequence if true: ...
Detail: ...

---
*<N> sub-threshold concerns considered and dropped.*

Unfalsifiable items → Section 8 (Unfalsifiable / Out of Scope):

**Declined: <item>** — unfalsifiable value claim; out of scope

---

S8 — Forced Verdict

What it produces: The verdict, Bottom Line, and mandatory What Would Change the Verdict section.

How to execute:

1. Count Tier-1 objections. Apply the four-tier verdict scale from the agent file. Pick exactly one. No hedging.
2. Write the Bottom Line: 2–3 sentences referencing only Tier-1 objections. Do not mention Tier-2 here.
3. Write What Would Change the Verdict: explicit — what evidence, fix, or test would move this verdict one tier up. This section is mandatory.

Output format:

# Verdict: <SURVIVES | SURVIVES WITH CAVEATS | WOUNDED | DOES NOT SURVIVE>

**Target:** <diff source / PR URL>
**Mode:** change
**Scope:** <scope string or "entire diff">
**Timestamp:** <ISO 8601>

## Bottom Line (S8)

<2–3 sentences. Reference O<N> IDs only from Tier-1. State why the verdict is what it is.>

...

## What Would Change the Verdict (S8)

- Adding <X> would move this from <current verdict> to <next-tier verdict>: <reasoning>
- Demonstrating <Y> would withdraw O<N>: <what evidence is needed>

---

Output Composition

The final artifact assembles sections in this order:

Section	Content	Produced by
1 — Header	Verdict (first line), target, mode, scope, timestamp, reviewer model	S8
2 — Bottom Line	2–3 sentence rationale, Tier-1 refs only	S8
3 — Objections	Tier-1 + Tier-2 numbered blocks	S7
4 — Citation Shepardizing	OMITTED in change mode	—
5 — Key Assumptions Surfaced	Assumption table	S2
6 — Pre-mortem Failure Modes	PM items	S4
7 — ACH Matrix	OMITTED in change mode	—
8 — Unfalsifiable / Out of Scope	Declined items	S7
9 — What Would Change the Verdict	Explicit upgrade conditions	S8

Write the artifact to: ~/.pi/agent/reviews/<slug>-<timestamp>.md

Print the artifact path at the end of the session.

If --emit-json flag is set OR the agent was spawned by another agent, also write a sidecar JSON at the same path with .json extension.