| name | change-review |
| description | Review a branch, pull request, commit range, or working-tree diff on two axes: repository standards and the originating requirements. Use for explicit code or PR review, independent pre-merge quality gates, and checking an implementation against its specification. Do not use when there is no change set to inspect or the task is only to implement a known fix. |
Change Review
This skill is the two-axis review (standards and specification). For a fast bug-focused pass over the working diff, the bundled /code-review command is the lighter option; use this skill when the change must also be checked against its stated requirements.
Review the exact change against two independent questions: whether it is built correctly and whether it builds the requested thing.
Read references/evidence.md when calibrating scope, finding usefulness, or severity. If delegation is explicitly authorized, apply delegate-work and assign only distinct review axes such as correctness, security, external compatibility, or rendered interface quality; keep synthesis and deduplication in the main session.
Respect the Review Contract
- Treat a review-only request as read-only. Do not modify code, resolve findings, or change repository state.
- When the user explicitly requests review and fixes, complete the evidence-based review first, then correct supported findings and verify the result.
- Review only the requested diff and directly affected behavior. Do not turn the review into a general codebase audit.
- Preserve the distinction between repository standards and product requirements.
Pin the Review Scope
Resolve and verify the fixed point before reviewing:
- the merge base, branch, commit, tag, or working-tree state;
- committed, staged, unstaged, and untracked changes in scope;
- generated, vendored, lock, schema, and migration files affected by the change.
Fail clearly on an invalid base or empty diff. Do not silently substitute a different comparison.
Read the full relevant diff and enough surrounding code to understand runtime behavior. Trace changed interfaces to important callers, consumers, tests, configuration, and data boundaries.
Gather the Standards Evidence
Collect the instruction and convention sources that govern the changed files:
- applicable
CLAUDE.md files and skill instructions;
- contribution, architecture, security, and style guidance;
- formatter, linter, compiler, test, and build configuration;
- established patterns in nearby maintained code;
- compatibility requirements from manifests and lockfiles.
Repository rules override generic preferences. Leave mechanically enforceable formatting to the project's tooling unless it causes a functional issue.
Gather the Specification Evidence
Locate the source of intent:
- the user's request and accepted clarifications;
- the active plan;
- an issue, specification, PR description, acceptance criteria, ADR, or migration document;
- tests that encode established public behavior.
If no specification exists, state that the specification axis cannot be completed. Do not infer requirements from the implementation under review.
Review the Standards Axis
Look for actionable defects in:
- correctness and failure handling;
- data integrity and compatibility;
- security, authorization, privacy, and secret handling;
- concurrency, lifecycle, resource ownership, and cleanup;
- performance when the changed path or evidence makes it relevant;
- public API and migration safety;
- test quality and observability;
- maintainability where complexity creates a concrete defect or regression risk;
- compliance with applicable repository instructions.
Treat code smells as prompts for investigation, not automatic violations. Do not report personal style preferences.
Apply the codebase-design vocabulary only when the diff creates concrete boundary, locality, or test-surface problems.
Review the Specification Axis
Map each requirement and acceptance criterion to the implemented behavior and evidence. Check for:
- missing or only partially implemented requirements;
- behavior that contradicts the requested outcome;
- scope added without authorization;
- unsupported assumptions;
- omitted edge cases explicitly required by the specification;
- changes that pass tests while solving the wrong problem.
Keep these findings separate from standards findings even when they point to the same line.
Validate Every Finding
Before reporting a finding:
- cite the exact file and narrowest useful line range;
- explain the causal path from the code to the user-visible or operational impact;
- verify the surrounding code does not already handle the case;
- use focused tests or read-only experiments when they materially increase confidence;
- assign severity from impact and likelihood, not stylistic preference;
- propose the smallest direction for remediation without implementing it.
Use priorities consistently:
- P0: immediate catastrophic or broadly exploitable failure;
- P1: serious defect likely to block release or cause data, security, or major functional harm;
- P2: real correctness or reliability defect with bounded impact;
- P3: lower-impact issue worth correcting but not release-blocking.
Exclude speculative, non-actionable, and already-covered concerns. Do not inflate the finding count.
Inspect Verification Quality
Confirm that tests and checks:
- exercise the changed production path;
- would fail on the relevant regression;
- cover required success and failure behavior;
- avoid tautological expected values and excessive implementation coupling;
- were actually executed when the review claims rely on their results.
Do not assume passing CI proves requirements coverage.
Present Findings First
Report actionable findings first, ordered by priority and then by file location. For each finding include:
- priority and concise title;
- file and line;
- violated standard or requirement;
- causal explanation and impact;
- evidence and focused remediation direction.
Then state material assumptions, unanswered questions, and residual verification gaps. End with a brief overall assessment.
If there are no actionable findings, say so directly and mention only material residual risks or unverified areas.
Completion Standard
Finish only when the entire scoped diff has been inspected, both available review axes have been evaluated independently, and every reported finding is grounded in a specific code path and source of expected behavior.
