name: review-llm-artifacts description: Detects common LLM coding agent artifacts by spawning four parallel subagents over the project or changed files. Scans files changed since main by default; use --all for full-project scan. Triggers on LLM cruft cleanup, agent-generated code review, dead code sweeps, test-quality passes, or when the user asks to scan the whole repo. disable-model-invocation: true

LLM Artifacts Review

Detect common artifacts left behind by LLM coding agents: over-abstraction, dead code, DRY violations in tests, verbose comments, and defensive overkill.

Hard gates (sequence)

Advance only when each pass condition is objectively true (prevents “review complete” without artifacts):

Arguments

Parse $ARGUMENTS for flags and optional path:

Step 1: Determine Scope

A. Changed files only (default):

Resolve the base ref explicitly and fail loudly if none exists — do not wrap the git merge-base call in || true, which would silently swallow a missing main/master ref and report "no files to scan" on repos that only have origin/main or use master. If no base ref is found, suggest the user pass --all instead of silently falling back.

BASE=$(for ref in main origin/main master origin/master; do
         git rev-parse --verify "$ref" >/dev/null 2>&1 && { echo "$ref"; break; }
       done)
if [ -z "$BASE" ]; then
  echo "error: no main/master ref found (checked main, origin/main, master, origin/master). Pass --all for a full-project scan." >&2
  exit 1
fi
MERGE_BASE=$(git merge-base HEAD "$BASE") || {
  echo "error: git merge-base HEAD $BASE failed." >&2
  exit 1
}
git diff --name-only "$MERGE_BASE..HEAD" | grep -E '\.(py|ts|tsx|js|jsx|go|rs|java|rb|swift|kt)$' || true

(The trailing || true on the grep is intentional — zero source-file matches is a legitimate empty-scope result, distinct from a failed base-ref resolution.)

B. Full project (--all):

From TARGET (default .), list source files and prune excluded dependency/build trees so find never descends into them. ! -path "*/foo/*" only filters the output; find still walks the tree (minutes of wasted I/O on large node_modules, target, etc.). Use -prune instead:

find "$TARGET" \
  \( -type d \( \
       -name node_modules -o -name .git -o -name vendor -o -name __pycache__ \
    -o -name .venv        -o -name venv -o -name dist   -o -name build \
    -o -name target       -o -name .next -o -name coverage -o -name .turbo \
  \) -prune \) -o \
  \( -type f \( \
       -name "*.py" -o -name "*.ts" -o -name "*.tsx" -o -name "*.js" -o -name "*.jsx" \
    -o -name "*.go" -o -name "*.rs" -o -name "*.java" -o -name "*.rb" \
    -o -name "*.swift" -o -name "*.kt" \
  \) -print \)

Large repos: The --all path can produce huge file lists. If file count exceeds 400, warn and suggest narrowing: pass a subdirectory as TARGET, or drop --all to fall back to the default changed-files scope. Still proceed unless the user explicitly cancels. (This warning does not fire on the default changed-files scope, which is already bounded by the PR diff.)

If no files are found, exit with:

No files to scan. Check the path, branch, or pass --all for a full-project scan.

Set scope in the report: "all" for --all, "changed" for the default changed-files scope.

Step 2: Detect Languages

Extract unique file extensions from the file list:

echo "$FILES" | sed 's/.*\.//' | sort -u

Map extensions to language names for the report:

• .py -> Python
• .ts, .tsx -> TypeScript
• .js, .jsx -> JavaScript
• .go -> Go
• .rs -> Rust
• .java -> Java
• .rb -> Ruby
• .swift -> Swift
• .kt -> Kotlin

Step 3: Spawn Parallel Subagents

If file count >= 4 OR --parallel flag is set, spawn 4 subagents via Task tool.

Each subagent MUST:

1. Load the skill: Skill(skill: "beagle-core:llm-artifacts-detection")
2. Review only its assigned category
3. Return findings in the structured format below

Subagent 1: Tests Agent

Focus: Testing anti-patterns from LLM generation

• DRY violations (repeated setup code, duplicate assertions)
• Testing library/framework code instead of application logic
• Wrong mock boundaries (mocking too much or too little)
• Overly verbose test names that describe implementation
• Tests that just mirror the implementation

Subagent 2: Dead Code Agent

Focus: Unused or obsolete code

• Unused imports, variables, functions, classes
• TODO/FIXME comments that should have been resolved
• Backwards compatibility code for removed features
• Orphaned test files for deleted code
• Commented-out code blocks
• Feature flags that are always on/off

Subagent 3: Abstraction Agent

Focus: Over-engineering patterns

• Unnecessary abstraction layers (interfaces for single implementations)
• Copy-paste drift (similar code that diverged slightly)
• Over-configuration (configurable things that never change)
• Premature generalization
• Factory/Builder patterns for simple object creation
• Deep inheritance hierarchies

Subagent 4: Style Agent

Focus: Verbose or defensive patterns

• Verbose comments explaining obvious code
• Defensive overkill (null checks on non-nullable values)
• Unnecessary type hints (dynamic languages with obvious types)
• Overly explicit error messages
• Redundant logging
• Self-documenting code with documentation

Step 4: Consolidate Findings

Prerequisite: G2 satisfied (all four category reviews finished successfully).

Wait for all subagents to complete, then:

1. Merge all findings into a single list
2. Assign unique IDs (1, 2, 3...)
3. Group by category for display

Step 5: Write JSON Report

Create .beagle directory if it doesn't exist:

mkdir -p .beagle

Write findings to .beagle/llm-artifacts-review.json:

{
  "version": "1.0.0",
  "created_at": "2024-01-15T10:30:00Z",
  "git_head": "abc1234",
  "scope": "all" | "changed",
  "target": ".",
  "files_scanned": 42,
  "languages": ["Python", "TypeScript", "Go"],
  "findings": [
    {
      "id": 1,
      "category": "tests" | "dead_code" | "abstraction" | "style",
      "type": "dry_violation" | "unused_import" | "over_abstraction" | "verbose_comment" | "...",
      "file": "src/utils/helper.py",
      "line": 42,
      "description": "Repeated setup code in 5 test functions",
      "suggestion": "Extract to a pytest fixture",
      "risk": "Low" | "Medium" | "High",
      "fix_safety": "Safe" | "Needs review",
      "fix_action": "refactor" | "delete" | "simplify" | "extract"
    }
  ],
  "summary": {
    "total": 15,
    "by_category": {
      "tests": 4,
      "dead_code": 5,
      "abstraction": 3,
      "style": 3
    },
    "by_risk": {
      "High": 2,
      "Medium": 8,
      "Low": 5
    },
    "by_fix_safety": {
      "Safe": 10,
      "Needs review": 5
    }
  }
}

Step 6: Display Summary

Prerequisite: G3 satisfied (JSON on disk and parseable).

## LLM Artifacts Review

**Scope:** Changed files since merge-base with main | Entire project under `<path>` (when `--all`)
**Files scanned:** 42
**Languages:** Python, TypeScript, Go

### Findings by Category
...
### Summary Table
...
### Next Steps

- Run `/beagle-core:verify-llm-artifacts` to confirm findings and drop false positives before fixing.
- Run `/beagle-core:fix-llm-artifacts` after verification (or to preview safe-only fixes).
- Review the JSON report at `.beagle/llm-artifacts-review.json`

Step 7: Verification (report integrity)

Before completing, verify the review executed correctly:

1. JSON validity: Confirm .beagle/llm-artifacts-review.json exists and is parseable
2. Subagent success: All 4 subagents completed without errors
3. Git HEAD captured: The git_head field is non-empty in the report
4. Staleness check: If a previous report exists, compare stored git_head to current HEAD and warn if different

python3 -c "import json; json.load(open('.beagle/llm-artifacts-review.json'))" 2>/dev/null && echo "✓ Valid JSON" || echo "✗ Invalid JSON"

STORED_HEAD=$(jq -r '.git_head' .beagle/llm-artifacts-review.json 2>/dev/null)
CURRENT_HEAD=$(git rev-parse --short HEAD)
if [ "$STORED_HEAD" != "$CURRENT_HEAD" ]; then
  echo "⚠️ Report was generated on $STORED_HEAD, current HEAD is $CURRENT_HEAD"
fi

If any verification fails, report the error and do not proceed.

Finding-level verification (precision, not JSON syntax) is a separate skill: /beagle-core:verify-llm-artifacts — run it before mass deletes or --fix on risky items.

Output Format for Each Finding

[FILE:LINE] **ISSUE_TYPE** (Risk, Fix Safety)
- Description
- Suggestion: Specific fix recommendation

Rules

• Follow Hard gates order; do not skip G3 (JSON before Step 6).
• Always load the beagle-core:llm-artifacts-detection skill first
• Use Task tool for parallel subagents when >= 4 files
• Every finding MUST have file:line reference
• Categorize risk honestly (don't inflate or deflate)
• Mark fix safety as "Safe" only if change is mechanical and reversible
• Create .beagle directory if needed
• Write JSON report before displaying summary
• Default scope is changed files since merge-base with main; pass --all for a full-project scan