v3.15.0 latest
March 2026
Design Pattern Classification (Free + Pro)
- + 19.1 Pattern detection (Free): classifies skills as Reviewer, Generator, Inversion, Pipeline, or Tool Wrapper based on the Google ADK taxonomy
- + 19.2-19.7 Pattern deep checks (Pro): validates pattern-specific requirements; criteria for Reviewers, output specs for Generators, question frameworks for Inversion, stage docs for Pipelines, API boundaries for Tool Wrappers
Artifact Contract Validation (Pro)
- + 17.6-17.9: validates
produces/consumes frontmatter fields, artifact metadata documentation, and discovery patterns
- + Flags undeclared artifact type references in body text (with code block exclusion to prevent false positives)
Trigger Collision Detection (Pro)
- + 20.1-20.4: cross-skill directory scan using Jaccard similarity on trigger word sets; flags overlaps at 50% (warning) and 85% (critical)
- + 20.5-20.7: artifact pipeline validation; detects orphan producers and missing consumers across skill directories
- + Runs automatically during
skillcheck scan
105 total checks across 20 categories. Sources: Google ADK skill design patterns, Anthropic skill taxonomy.
v3.14.0
March 2026
New Free Tier Checks
- + 4.8 Description trigger style: flags descriptions that read as capability summaries instead of trigger conditions
- + 4.9 Railroading detection: catches 5+ prescriptive phrases that reduce Claude's adaptability
- + 8.9 Gotchas section: recognizes gotchas/pitfalls/caveats documentation as a quality strength
New Pro Tier Checks
- + 10.7 Setup/config handling: flags skills referencing credentials without handling missing-config case
- + 10.8 Data storage path safety: warns about persistent data stored inside skill directory (won't survive upgrades)
87 total checks. Source: Anthropic's internal skill design insights.
v3.13.0
March 2026
New Frontmatter Fields
- +
effort field validation (low, medium, high)
- +
maxTurns field validation with runaway detection (>100)
- +
disallowedTools validation with allowed-tools overlap detection
- + Model aliases accepted:
opus, sonnet, haiku
- + Spec version updated to 2026-03-20
v3.12.0
March 2026
Skill Discovery
- +
skillcheck discover CLI command and skillcheck_discover MCP tool
- + Multi-platform scanning: Claude Code, Cursor, Windsurf, Codex CLI
- + Scans CLAUDE.md, .cursorrules, AGENTS.md, custom commands, hooks
- + Confidence scoring (HIGH/MEDIUM/LOW) per candidate
- + Platform auto-detection with per-candidate tagging
- + Redundancy detection across config files
- + Free: see candidates. Pro (
--generate): auto-create SKILL.md files
v3.11.0
March 2026
Anti-Pattern Detection
- + 4.7-desc-workflow-steps (Free): flags descriptions that summarize workflow steps
- + 12.5-no-exit-criteria: phased skills missing exit criteria per phase
- + 12.6-unbounded-iteration: catches unbounded "for each" loops
- + 15.6-subagent-no-return-format: subagent prompt checks
- + 12.7-verbosity-detection: flags unnecessary explanations of well-known concepts
- + 12.8-feedback-loop-detection: flags quality-critical skills lacking verify steps
- + Skipped checks shown as "not applicable" instead of silently omitted
- + Accurate passed count: "Passed: N / M applicable"
v3.10.0
March 2026
Agent Readiness (L0-L3)
- + 6 new validation pillars with 28 checks (prefixes 13-18, Pro tier)
- + Reference Integrity: dangling references, excessive count, organization
- + Eval Readiness: success criteria, input/output examples, binary verdicts
- + Orchestration Safety: budget caps, phase boundaries, human checkpoints
- + Autonomy Design: stop conditions, safety guardrails, rollback, idempotency
- + Composability: input/output contracts, mode awareness, interface sections
- + Observability: progress reporting, confidence levels, phase boundaries
- + L0-L3 maturity scoring for agent-ready skills
- + WASM web validator at validate.getskillcheck.com
- + 82 total checks across 18 categories
v3.9.0
March 2026
Claude Code v2.1.69-71 Sync
- + New tools in KnownTools: CronCreate, CronDelete, CronList, EnterWorktree
- + Quality check 8.8-uses-skill-dir-var for
${CLAUDE_SKILL_DIR}
- + Example XML block tracking in ambiguous term and wisdom checks
- + Description severity softened from required to recommended
- + Version moved from top-level to metadata block
v3.8.0
March 2026
Wisdom Detection & Format Lint
- + 4.6-wisdom-platitude (Free): detects generic advice that wastes tokens
- + 2.8-anti-pattern-format (Free): flags prose anti-pattern docs, suggests tables
- + Progressive disclosure via references/ directory
v3.7.0
March 2026
Progressive Disclosure & Skill Sync
- + SKILL.md uses references/ for context-efficient loading
- + Version sync across CLI, MCP server, and web server
v3.6.0
February 2026
Anthropic Guide Alignment
- + Aligned with "The Complete Guide to Building Skills for Claude" (Anthropic, Feb 2026)
- + 4.4-body-misplaced-routing: flags "When to Use" sections in body
- + Routing trigger content moved to description field
v3.5.0
February 2026
Community Patterns
- + Checks informed by scanning 1434 community skills
- + scan command for batch validation of skill repositories
- + report command for HTML validation reports
v3.4.0
January 2026
Quality Patterns (Strengths)
- + SkillCheck now recognizes positive patterns, not just issues
- + Free: example section, error handling, trigger phrases, output format
- + Pro: negative triggers, boundary conditions, version pinning
v3.3.0
January 2026
Description & Claude Code Fields
- + 4.4-desc-use-when: suggests "Use when..." description format
- + 4.5-desc-no-triggers: warns when descriptions lack trigger phrases
- + Claude Code frontmatter validation: model, context, agent, hooks
v3.1.0
January 2026
Configuration & Plugins
- + YAML configuration via .skillcheck.yaml
- + Plugin system for custom checks
- + Audit logging for compliance
- + Custom rules with pattern matching
v3.0.0
December 2025
Knowledge Source Architecture
- + SKILL.md contains complete validation knowledge (no MCP dependency)
- + Architecture rewrite: skill file is the source of truth
v2.0.0
December 2025
agentskills Spec Alignment
- + Aligned with official agentskills specification
- + Breaking: version field no longer required, allowed-tools format changed
v1.0.0
December 2025
Initial Release
- + CLI tool for validating Claude Code skills
- + MCP server for Claude Code integration
- + Web server with API endpoint