Pattern Analyzer Skill | Agent Skills

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Pattern Analyzer

L3 Worker that analyzes a single architectural pattern against best practices and calculates 4 scores.

Purpose & Scope

Analyze ONE pattern per invocation (receives pattern name, locations, best practices from coordinator)
Find all implementations in codebase (Glob/Grep)
Validate implementation exists and works
Calculate 4 scores: compliance, completeness, quality, implementation
Identify gaps and issues with severity and effort estimates
Return structured analysis result to coordinator

Out of Scope (owned by ln-624-code-quality-auditor):

Cyclomatic complexity thresholds (>10, >20)
Method/class length thresholds (>50, >100, >500 lines)
Quality Score focuses on pattern-specific quality (SOLID within pattern, pattern-level smells), not generic code metrics

Input (from ln-640 coordinator)

- pattern: string          # Pattern name (e.g., "Job Processing")
- locations: string[]      # Known file paths/directories
- bestPractices: object    # Best practices from MCP Ref/Context7/WebSearch
- output_dir: string       # e.g., "docs/project/.audit"

Note: All patterns arrive pre-verified (passed ln-640 Phase 1d applicability gate with >= 2 structural components confirmed).

Workflow

Phase 1: Find Implementations

MANDATORY READ: Load ../ln-640-pattern-evolution-auditor/references/pattern_library.md — use "Pattern Detection (Grep)" table for detection keywords per pattern.

IF pattern.source == "adaptive":
  # Pattern discovered by coordinator Phase 1b — evidence already provided
  files = pattern.evidence.files
  SKIP detection keyword search (already done in Phase 1b)
ELSE:
  # Baseline pattern — use library detection keywords
  files = Glob(locations)
  additional = Grep("{pattern_keywords}", "**/*.{ts,js,py,rb,cs,java}")
  files = deduplicate(files + additional)

Phase 2: Read and Analyze Code

FOR EACH file IN files (limit: 10 key files):
  Read(file)
  Extract: components, patterns, error handling, logging, tests

Phase 3: Calculate 4 Scores

MANDATORY READ: Load ../ln-640-pattern-evolution-auditor/references/scoring_rules.md — follow Detection column for each criterion.

| Score | Source in scoring_rules.md | Max | |-------|---------------------------|-----| | Compliance | "Compliance Score" section — industry standard, naming, conventions, anti-patterns | 100 | | Completeness | "Completeness Score" section — required components table (per pattern), error handling, tests | 100 | | Quality | "Quality Score" section — method length, complexity, code smells, SOLID | 100 | | Implementation | "Implementation Score" section — compiles, production usage, integration, monitoring | 100 |

Scoring process for each criterion:

Run the Detection Grep/Glob from scoring_rules.md
If matches found → add points per criterion
If anti-pattern/smell detected → subtract per deduction table
Document evidence: file path + line for each score justification

Phase 4: Identify Issues and Gaps

FOR EACH bestPractice NOT implemented:
  issues.append({
    severity: "HIGH" | "MEDIUM" | "LOW",
    category: "compliance" | "completeness" | "quality" | "implementation",
    issue: description,
    suggestion: how to fix,
    effort: "S" | "M" | "L"
  })

gaps = {
  missingComponents: required components not found in code,
  inconsistencies: conflicting or incomplete implementations
}

Phase 5: Calculate Overall Score

overall_score = average(compliance, completeness, quality, implementation) / 10

Phase 6: Write Report

MANDATORY READ: Load shared/templates/audit_worker_report_template.md for file format (ln-640 section: 4-score AUDIT-META + DATA-EXTENDED).

# Build pattern name slug: "Job Processing" → "job-processing"
slug = pattern.name.lower().replace(" ", "-")

# Build markdown report in memory with:
# - AUDIT-META (4-score variant: score + score_compliance/completeness/quality/implementation)
# - Checks table (compliance_check, completeness_check, quality_check, implementation_check)
# - Findings table (issues sorted by severity)
# - DATA-EXTENDED: {pattern, codeReferences, gaps, recommendations}

Write to {output_dir}/641-pattern-{slug}.md (atomic single Write call)

Phase 7: Return Summary

Report written: docs/project/.audit/641-pattern-job-processing.md
Score: 7.9/10 (C:72 K:85 Q:68 I:90) | Issues: 3 (H:1 M:2 L:0)

Critical Rules

One pattern only: Analyze only the pattern passed by coordinator
Read before score: Never score without reading actual code
Detection-based scoring: Use Grep/Glob patterns from scoring_rules.md, not assumptions
Effort estimates: Always provide S/M/L for each issue
Code references: Always include file paths for findings

Definition of Done

All implementations found via Glob/Grep (using pattern_library.md keywords or adaptive evidence)
Key files read and analyzed
4 scores calculated using scoring_rules.md Detection patterns
Issues identified with severity, category, suggestion, effort
Gaps documented (missing components, inconsistencies)
Recommendations provided
Report written to {output_dir}/641-pattern-{slug}.md (atomic single Write call)
Summary returned to coordinator

Reference Files

Worker report template: shared/templates/audit_worker_report_template.md
Scoring rules: ../ln-640-pattern-evolution-auditor/references/scoring_rules.md
Pattern library: ../ln-640-pattern-evolution-auditor/references/pattern_library.md

Version: 2.0.0 Last Updated: 2026-02-08

Agent Skills: Pattern Analyzer

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