anthropic-validator

name	anthropic-validator
description	Validates Claude Code assets (skills, hooks, agents, commands, MCP servers, plugins) against official Anthropic standards. Fetches latest docs dynamically and produces structured validation reports.
when_to_use	When validating Claude Code assets (skills, hooks, agents, commands, MCP servers, plugins) against official Anthropic standards before release, after creation, or when auditing for spec compliance.
user-invocable	true
allowed-tools	["AskUserQuestion","Glob","Read","Task","Write"]
version	1.1.1
author	Ashay Kubal @ Qball Inc.

Anthropic Validator

Validates Claude Code assets against official Anthropic standards using dynamic documentation fetching and critical analysis.

---

Overview

The Problem

Claude Code evolves rapidly. Static checklists become outdated. Assets created months ago may violate current standards, and new features may not be reflected in embedded validation rules.

The Solution

This skill provides dynamic validation by:

1. Fetching latest standards from official Claude Code documentation
2. Critically analyzing assets against those standards
3. Producing actionable reports with specific violations and remediation

Design Pattern: Main Context Orchestration

This skill uses Main Context Orchestration — you (Claude) follow the instructions below to orchestrate sub-agents sequentially. This is required because sub-agents cannot spawn other sub-agents.

┌─────────────────────────────────────────────────────────────┐
│                   MAIN CONTEXT (You)                         │
│                                                             │
│  1. Load this skill (anthropic-validator)                   │
│  2. Determine asset type → load matching references file    │
│  3. Spawn claude-code-guide → fetch latest standards        │
│  4. Read output (direct response)                           │
│  5. Spawn bulwark-standards-reviewer → analyze asset        │
│  6. Read validation report from logs/validations/           │
│  7. Present summary to user                                 │
│                                                             │
└─────────────────────────────────────────────────────────────┘

Invocation

# Single asset validation
/anthropic-validator skills/my-skill/SKILL.md

# Batch validation (directory)
/anthropic-validator skills/

# Context inference (validates current file in context)
/anthropic-validator

---

Validation Workflow

Step 0: Resolve Target Asset

IMPORTANT: When this skill is invoked, first resolve what to validate:

IF $ARGUMENTS is provided (e.g., /anthropic-validator path/to/file):
    target_path = $1

    IF target_path ends with "/" OR is a directory:
        mode = "batch"
        → Skip to "Batch Validation" section below
    ELSE:
        mode = "single"
        → Continue with Step 1 for single-file validation

ELSE (no arguments, context inference):
    Look for Claude Code assets in recent conversation context
    IF found: validate that asset (single mode)
    ELSE: Ask user what to validate

Argument Reference:

• $ARGUMENTS — Full argument string passed to skill
• $1 — First positional argument (the path)

Workflow Routing:

• Single file → Continue with Steps 1-4 below
• Directory (batch) → Jump to "Batch Validation" section

Step 1: Determine Asset Type & Load Per-Type Reference

For the resolved target_path, match against these patterns and load the corresponding references/{type}-validation.md file for asset-specific workflow + validation points:

Path Pattern	Asset Type	Reference File
skills/*/SKILL.md	Skill	references/skills-validation.md
hooks/hooks.json or *.hooks.json	Hooks	references/hooks-validation.md
agents/*.md or .claude/agents/*.md	Agent	references/agents-validation.md
commands/*.md	Command	references/commands-validation.md
mcp/ or *-mcp-server*	MCP Server	references/mcp-validation.md
.claude-plugin/plugin.json	Plugin	references/plugins-validation.md

The loaded reference file provides:

• The official documentation URL for the asset type
• Asset-type-specific validation workflow steps
• Key validation points (frontmatter fields, required structure, etc.)
• Fallback checklist pointer (used if doc fetch fails — see Fallback Behavior section)

Step 2: Fetch Latest Standards

Spawn claude-code-guide agent with the documentation URL from the loaded references file:

GOAL: Fetch current standards for {asset_type} from official Claude Code docs

CONSTRAINTS:
- Only use official Anthropic documentation
- Report what IS supported vs what is NOT
- Include any recent changes or deprecations

CONTEXT:
- Documentation URL: {URL from references/{type}-validation.md}
- Capability being validated: {asset_type}

OUTPUT:
- Current supported fields/features
- Required vs optional elements
- Common pitfalls or mistakes
- Any version-specific notes

Step 2.5: Gather Supporting Files (Skills Only)

Scope: This step applies ONLY to asset_type == "skill". Non-skill validations (agents, commands, MCP, plugins, hooks) MUST skip this step and proceed directly to Step 3 with supporting_files = null in the CONTEXT block.

For skills, check for supporting subdirectories and files:

IF asset_type == "skill":
    1. Check for references/ subdirectory
       - List all files if present
       - Note: references/ is OPTIONAL (not all skills have it)

    2. Check for other common subdirectories
       - examples/, scripts/, templates/, data/
       - List files if present

    3. Scan SKILL.md for file references
       - Look for patterns: `references/*.md`, `examples/*`, etc.
       - Verify referenced files exist

    4. Build supporting_files inventory:
       supporting_files = {
         references: [list of files or "none"],
         examples: [list of files or "none"],
         scripts: [list of files or "none"],
         referenced_but_missing: [any files mentioned but not found]
       }

Step 3: Critical Analysis

Spawn bulwark-standards-reviewer agent (Task tool with subagent_type: bulwark-standards-reviewer):

GOAL: Critically analyze {asset_path} against fetched standards

CONSTRAINTS:
- Be thorough — check every requirement
- Rate findings by severity (Critical/High/Medium/Low)
- Provide specific remediation for each finding
- Do NOT modify the asset, only report
- Only flag missing references/ if the skill explicitly references files that don't exist
- Validate tools/fields against DOCUMENTATION, not by attempting to use them
  (The reviewer may not have access to all tools — don't conflate "I can't use this" with "this is invalid")
- Apply the three-tier frontmatter field classification (see "Bulwark-Adopted Fields
  Allowlist" section below) — adopted fields are informational notes, not violations;
  unknown fields remain HIGH-severity violations.

CONTEXT:
- Asset to validate: {asset_content}
- Current standards: {fetched_standards from Step 2}
- Asset type: {asset_type}
- Per-type reference: {contents of references/{type}-validation.md from Step 1}
- Supporting files inventory: {supporting_files from Step 2.5, if skill}
- Referenced files verified: {yes/no with details}
- Bulwark-Adopted Fields Allowlist (DO NOT flag as violations — emit informational notes):
  Three frontmatter fields are intentionally adopted by Bulwark as non-Anthropic-official
  but standardized conventions. The reviewer MUST classify these as
  `bulwark_adopted_fields` notes, not as violations:
  * `version` — semver string for skill/agent traceability across releases
  * `author` — attribution string (e.g., "Ashay Kubal @ Qball Inc.")
  * `skills` — applies ONLY to skill frontmatter (`SKILL.md`); for agent frontmatter
    (`.claude/agents/*.md`), `skills:` IS Anthropic-official and should be classified
    accordingly. The Bulwark adoption is the skill-frontmatter use case.
  Any other frontmatter field not in the official Anthropic spec for the asset type
  remains an `unknown` field and MUST be reported as a HIGH-severity violation.
- Known conventions (DO NOT flag as high/critical — classify as informational):
  The following patterns are intentional conventions backed by empirical testing.
  LLM agents reliably ignore behavioral-register instructions ("You always verify...")
  but comply with imperative-register instructions ("You MUST verify..."). These
  patterns have been validated across Opus and Sonnet models. Treat as informational
  only — note the divergence from pure Anthropic style but do NOT elevate severity:
  * Pre-Flight Gate sections with MUST/MUST NOT binding language
  * Imperative Protocol sections (step-by-step operational instructions)
  * Permissions Setup sections documenting settings.json configuration
  * Completion Checklists with checkbox items
  * DO/DO NOT mission sections
  * Tool Usage Constraints with Allowed/Forbidden per tool

OUTPUT:
Write structured YAML to logs/validations/{asset-name}-{timestamp}.yaml
Schema MUST include a top-level `bulwark_adopted_fields` array (separate from
`findings`) listing each adopted field detected with its value.
Schema MUST also include a top-level `reviewed_files: [...]` list (Stop-hook
contract — see Output Format section). Include any script/.sh files referenced
by the validated asset; empty list `[]` if the asset is .md/.json only.

Step 4: Present Results

Summarize findings to user in human-readable format (see Output Format section).

---

Bulwark-Adopted Fields Allowlist

Three frontmatter fields are non-Anthropic-official but intentionally standardized across Bulwark assets. The validator classifies them as bulwark-adopted — emitting informational notes in the report's bulwark_adopted_fields section, not counting them as violations against summary counters or verdict logic.

Three-Tier Classification

Tier	Definition	Validator Behavior
official	Field is in the canonical Anthropic spec for this asset type	Validate type/value per spec; flag mismatches as violations at appropriate severity
bulwark-adopted	Field is non-official but intentionally standardized in Bulwark	Emit info-level note in bulwark_adopted_fields; do not add to violation counters
unknown	Field is in neither category	Flag as HIGH violation — preserves the validator's drift-catching function

The Three Adopted Fields

Field	Adoption Rationale	Asset Types
version	Semver traceability across skill/agent releases. Operationally required for downstream consumers to know which version they have installed.	Skills + Agents
author	Attribution. Uniform value "Ashay Kubal @ Qball Inc." across first-party Bulwark assets; user-prompted for skills generated externally via create-skill.	Skills + Agents
skills	Cross-skill dependency declaration. Note: skills: IS officially documented for agent frontmatter (.claude/agents/*.md); it is not documented for skill frontmatter (SKILL.md). The Bulwark adoption applies only to the skill-frontmatter use case — for agents, treat skills as official.	Skills (adopted) / Agents (official)

Promotion Path

If Anthropic publishes a spec update that formalizes any of these fields:

1. Move the field from the bulwark-adopted list to the appropriate official validation table.
2. Remove the adopted-field note logic for that field.
3. Update references/{skills,agents,hooks,...}-validation.md and matching *-checklist.md to reflect the change.
4. Update the "Last Verified" date stamps on the relevant tables.

This is intentionally a single-config change — the data-driven structure (a list of field names per tier) makes promotion trivial.

Last Verified

• 2026-04-26 (Session 110, P10.3) — verified against Anthropic skills spec at https://code.claude.com/docs/en/skills (none of version, author, skills documented for skill frontmatter); skills confirmed documented for agent frontmatter at https://docs.anthropic.com/en/docs/claude-code/sub-agents.

Sync this section whenever Anthropic publishes spec updates that affect frontmatter fields.

---

Per-Asset-Type Validation Details

Asset-type-specific workflow + key validation points live in references/:

• Skills: references/skills-validation.md
• Hooks: references/hooks-validation.md
• Agents: references/agents-validation.md
• Commands: references/commands-validation.md
• MCP: references/mcp-validation.md
• Plugins: references/plugins-validation.md

Step 1 above routes to the correct file based on detected asset type. Each reference file contains the official documentation URL, the asset-specific validation workflow, the key validation points (fields, requirements, severities), and the fallback checklist pointer.

Fallback checklists (used when claude-code-guide doc fetch fails) live in the same directory: references/{type}-checklist.md.

---

Batch Validation

When validating a directory:

1. Glob all matching files based on asset type patterns
2. For each asset INDIVIDUALLY:
   • Run the FULL single-asset validation workflow (Steps 1-4)
   • Spawn bulwark-standards-reviewer with ONLY that one asset
   • Write individual report to logs/validations/
   • DO NOT combine multiple assets into one reviewer context
3. After all assets validated, aggregate results into summary report

CRITICAL: Do NOT frontload all assets into a single reviewer context. This causes shallow analysis due to context overload. Each asset must be validated with full depth individually, then results aggregated.

Batch Output

logs/validations/
├── batch-summary-{timestamp}.yaml    # Aggregate summary
├── skill-one-{timestamp}.yaml        # Individual reports
├── skill-two-{timestamp}.yaml
└── ...

Batch Summary Format

batch_validation:
  metadata:
    directory: "{path}"
    timestamp: "{ISO-8601}"
    total_assets: 5

  results:
    passed: 3
    failed: 2

  failures:
    - asset: "skills/broken-skill/SKILL.md"
      critical_count: 1
      report: "logs/validations/broken-skill-{timestamp}.yaml"

---

Output Format

YAML Report (logs/validations/)

# Top-level — required for Stop-hook per-file pipeline-recursion suppression.
# List any script/.sh files referenced by the validated asset (asset itself
# is typically .md/.json which the accumulator excludes). Paths relative to
# ${CLAUDE_PROJECT_DIR}. Empty list `[]` is valid and common (asset-only
# validation). Missing field disables suppression for this log (strict mode).
reviewed_files:
  - scripts/hooks/enforce-quality.sh

validation_report:
  metadata:
    asset: "{file_path}"
    asset_type: skill | hook | agent | command | mcp | plugin
    timestamp: "{ISO-8601}"
    validator: "bulwark-standards-reviewer"
    standards_source: fetched | fallback

  findings:
    # Official-spec violations only — bulwark-adopted fields are NOT listed here.
    - severity: critical | high | medium | low
      rule: "{standard being checked}"
      violation: "{what is wrong}"
      location: "{line or field}"
      remediation: "{how to fix}"

  bulwark_adopted_fields:
    # Non-Anthropic-official fields detected that ARE intentionally adopted by Bulwark.
    # These are informational notes — they do NOT count against the verdict.
    - field: version
      value: "1.0.0"
      classification: bulwark-adopted
      note: "Bulwark-adopted convention for traceability across releases."
    - field: author
      value: "Ashay Kubal @ Qball Inc."
      classification: bulwark-adopted
      note: "Bulwark-adopted convention for attribution."
    - field: skills
      value: ["subagent-prompting"]
      classification: bulwark-adopted
      note: "Documentary cross-skill dependency declaration. Anthropic parser ignores unknown fields."

  summary:
    official_spec_violations: 0
    bulwark_adopted_fields_detected: 0
    critical: 0
    high: 0
    medium: 0
    low: 0
    verdict: pass | fail
    notes: "{any additional context}"

Human-Readable Summary

Validation: skills/my-skill/SKILL.md
Standards: Fetched from official docs (2026-04-26)
Verdict: FAIL (2 critical, 1 high)

Official-Spec Violations:
  Critical:
    - Missing required 'description' field in frontmatter
    - SKILL.md exceeds 500 line limit (612 lines)
  High:
    - 'agent' field uses unsupported value 'gpt-4'

Bulwark-Adopted Fields Detected (informational, not violations):
  - version: "1.0.0"
  - author: "Ashay Kubal @ Qball Inc."

Full report: logs/validations/my-skill-2026-04-26T10-30-00.yaml

Severity Definitions

Severity	Definition	Examples
Critical	Blocks functionality, violates required standards	Missing required frontmatter, wrong file location
High	Significant issue, should fix before release	Deprecated field, exceeds limits
Medium	Quality improvement, recommended	Missing optional fields
Low	Style/naming suggestions	Naming conventions

Verdict Logic

# Field names align with the YAML summary schema above.
if summary.critical >= 1:
    verdict = "fail"
else:
    verdict = "pass"
# Always list ALL findings regardless of verdict.
# Bulwark-adopted field detections are NOT findings — they appear in
# the dedicated `bulwark_adopted_fields` section and do NOT affect verdict.

---

Fallback Behavior

When claude-code-guide fetch fails:

1. Log warning: "Could not fetch latest standards, using embedded checklist"
2. Set standards_source: fallback in report
3. Use embedded checklist from references/{type}-checklist.md (the per-asset-type fallback file referenced in references/{type}-validation.md)
4. Continue validation
5. Include note in summary: "Validated against potentially outdated standards"

---

Diagnostic Output

All validation runs write diagnostic data to:

logs/diagnostics/anthropic-validator-{ISO-8601-timestamp}.yaml

Use ISO-8601 with hyphens for filename safety, e.g. 2026-04-26T14-00-00. Same convention applies to validation reports under logs/validations/.

Diagnostic Schema

# Top-level — required for Stop-hook per-file pipeline-recursion suppression.
# Diagnostic logs typically reference no scripts directly (the validation
# workflow operates on the asset itself). Empty list `[]` is the common case;
# include any script paths only if the diagnostic explicitly cites them.
reviewed_files: []

diagnostic:
  skill: anthropic-validator
  timestamp: "{ISO-8601}"

  invocation:
    asset_path: "{input}"
    asset_type: "{detected type}"
    batch_mode: true | false

  execution:
    standards_fetch:
      agent: claude-code-guide
      success: true | false
      fallback_used: true | false
    analysis:
      agent: bulwark-standards-reviewer
      findings_count: 0

  output:
    report_path: "logs/validations/{name}.yaml"
    verdict: pass | fail

---

Related Skills

• subagent-prompting (P0.1) — 4-part template for agent invocation
• subagent-output-templating (P0.2) — Output format for logs

Related Agents

• bulwark-standards-reviewer — Critical analysis agent (invoked by this skill)
• claude-code-guide — Built-in agent for documentation fetching