---

name: eval-review description: Review LLM-generated diff classifications for the diffview eval system. Use when the user invokes this skill or pastes yanked case data from evalreview (containing "# Diff Classification Review" header). Evaluates whether classifications accurately help code reviewers, provides pass/fail verdict with detailed critique.

Eval Review

Review diff classification cases to determine if the LLM correctly categorized hunks, identified change type, and told a coherent story.

Why Classifications Matter

The classification drives a story-guided review UI where:

1. PRs become "pages" — Each story section is a page showing a subset of hunks with narration
2. Categories control visibility:
   • core → Shown prominently. Reviewer must see this.
   • supporting → Shown de-emphasized. Worth a glance.
   • noise → Suppressed. Don't waste reviewer attention.
3. Narration guides understanding — Section explanations tell the reviewer what they're looking at and why it matters

The stakes: A miscategorized hunk either hides something important (core → noise) or wastes attention on trivia (noise → core). The classifier's job is to help reviewers focus.

Workflow

1. Receive case data — User pastes yanked content from evalreview (y key)
2. Gather context — Fetch additional context to verify claims
3. Evaluate — Apply criteria tables below
4. Verdict — Provide pass/fail with actionable critique

Context Discovery

Before evaluating, gather this context (extract repo, branch, commit hashes from the input):

1. Beads Issue (intent)

bd show <branch>   # e.g., bd show diffview-7yu

Gives: Why was this change made? What problem does it solve?

2. Full Files at Commit (surrounding code)

git show <hash>:<filepath>   # e.g., git show abc123:pkg/auth/login.go

Gives: See functions around the changed hunks. Is a "systematic" hunk actually changing behavior?

3. PR Description (if exists)

gh pr list --head <branch> --json number,title,body --jq '.[0]'

Gives: Author's description of the change, which helps verify summary accuracy.

4. Recent History of Changed Files

git log --oneline -3 <filepath>

Gives: Is this a refactor of recent work, or new functionality?

What each context verifies:

• Beads issue → change_type, narrative pattern
• Full files → hunk categories (core vs systematic)
• PR description → summary quality
• File history → feature vs refactor distinction

Evaluation Criteria

Change Types

Type	Correct when...	Misapplied when...
bugfix	Removes incorrect behavior or adds missing behavior that should have existed	Adds genuinely new capability (→ feature)
feature	Adds new capability that didn't exist before	Restructures existing capability (→ refactor)
refactor	Same behavior, different structure	Behavior actually changes
chore	Maintenance: deps, CI, build scripts. No functional changes	Includes functional changes
docs	Only docs/comments change	Code changes accompany doc changes

Narratives

Pattern	Correct when...	Misapplied when...
cause-effect	Clear problem → solution structure	No identifiable "problem"
core-periphery	One central change causes ripples	Changes are independent
before-after	Transformation from old to new pattern	No clear "before" state
rule-instances	Pattern defined once, applied N times	Each change is unique
entry-implementation	Public API defined, then implementation	No clear API boundary

Hunk Categories

Category	Correct when...	Dangerous if wrong
core	Changes program behavior. Must review	Marked systematic → hides bugs
systematic	Mechanical: renames, params, boilerplate	Marked core → wastes attention
refactoring	Code moves without behavior change	Behavior actually changes
noise	Formatting, whitespace only	Real changes hidden

Key test: If skipping could cause a reviewer to miss a bug, it's core.

Beads/Issue Tracker Changes

Beads files (.beads/) require special handling based on what they affect:

Change Scope	Category	UI Treatment	Rationale
Current issue status/closed	noise	Suppress	Reviewer is already reviewing this work
Current issue notes updated	noise	Suppress	Mechanical bookkeeping
Dependency edges added/removed	noise	Suppress	Graph maintenance
Wiring notes to other issues	supporting	Show (de-emphasized)	Documents decisions for future work
New issues created	supporting	Show (de-emphasized)	Discovered scope worth noting

The rule: Changes scoped to <current-branch-id> → noise. Changes propagating context to other issue IDs → supporting.

Mixed hunks: If a beads hunk contains both current-issue bookkeeping and downstream wiring notes, categorize by dominant content. Pure status updates = noise; substantive wiring notes = supporting.

Section Roles

Role	Contains...
problem	What's broken/missing
fix	The solution
test	Test additions/modifications
core	Essential logic changes
supporting	Enables but isn't focus (including exceptions to patterns)
pattern	Repeatable approach being applied
interface	API/interface definitions
cleanup	Removing old code

Grouping test: Hunks in a section should be semantically related, not just in the same file.

Output Format

Use this structured format for consistent, scannable reviews:

## Verdict: PASS | FAIL

[One sentence summary of the classification quality]

## Evaluation

### Change Type: [type] — ✓ Correct | ✗ Wrong
[1-2 sentences explaining why this type fits or doesn't fit]

### Narrative: [pattern] — ✓ Correct | ✗ Wrong
[1-2 sentences explaining why this pattern fits or doesn't fit]

### Hunk Assignments
| Hunk | Assigned | Correct? | Issue |
|------|----------|----------|-------|
| file.go:H0 | core | ✓ | — |
| test.go:H0 | test | ✓ | — |
| .beads:H0 | supporting | ✓ | Could argue noise |

### Section Structure
[Are sections well-organized? Do explanations help reviewers?]

## Context Gathered
- `bd show <id>` — [what it revealed]
- `git log <file>` — [what it revealed]

Formatting rules:

• Use ✓ for correct, ✗ for incorrect
• Keep each evaluation to 1-2 sentences max
• The hunk table should list every hunk with quick assessment
• If FAIL, the "Issue" column should state what it should be