Anthropic Validator

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 Static checklists become outdated.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. Follow section instructions for asset type              │
│  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

For the resolved target_path, match against these patterns:

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

Step 2: Fetch Latest Standards

Spawn claude-code-guide agent with the appropriate documentation URL:

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: {see section below for URL}
- 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)

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")

CONTEXT:
- Asset to validate: {asset_content}
- Current standards: {fetched_standards from Step 2}
- Asset type: {asset_type}
- Supporting files inventory: {supporting_files from Step 2.5, if skill}
- Referenced files verified: {yes/no with details}
- 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

Step 4: Present Results

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

---

Skills Validation

Official Documentation

https://docs.anthropic.com/en/docs/claude-code/skills

Validation Workflow

1. Read the skill's SKILL.md file
2. Check for supporting subdirectories:

• references/ - list files if present (OPTIONAL - not all skills need this)
• examples/, scripts/, templates/, data/ - list if present

1. Verify referenced files - scan SKILL.md for file mentions (references/*.md, etc.) and confirm they exist
2. Spawn claude-code-guide with prompt:

`` Fetch current standards for Claude Code skills from https://docs.anthropic.com/en/docs/claude-code/skills Focus on: frontmatter fields, SKILL.md structure, user-invocable, agent field, context field ``

1. Spawn bulwark-standards-reviewer with:

• Skill content
• Fetched standards
• Supporting files inventory (list of files in references/, examples/, etc.)
• Referenced files verification (which mentioned files exist/missing)

1. Write report to logs/validations/

Important: A missing references/ folder is NOT a violation unless the skill explicitly references files that don't exist. Many skills are self-contained and don't need supporting files.

Key Validation Points

| Field | Requirement | |-------|-------------| | name | Required, matches directory name | | description | Required, concise explanation | | user-invocable | Boolean, controls / menu visibility | | agent | Optional: haiku, sonnet, or opus for model selection | | context | Optional: fork for isolated execution | | skills | Optional: array of skills to load | | tools | Optional: array of allowed tools |

Fallback Checklist

If doc fetch fails, use: references/skills-checklist.md

---

Hooks Validation

Official Documentation

https://docs.anthropic.com/en/docs/claude-code/hooks

Validation Workflow

1. Read the hooks configuration file
2. Spawn claude-code-guide with prompt:

`` Fetch current standards for Claude Code hooks from https://docs.anthropic.com/en/docs/claude-code/hooks Focus on: hook types, matcher patterns, once field, command format, environment variables ``

1. Spawn bulwark-standards-reviewer with hooks content and fetched standards
2. Write report to logs/validations/

Key Validation Points

| Field | Requirement | |-------|-------------| | Hook types | PreToolUse, PostToolUse, SubagentStart, SubagentStop, Notification | | matcher | Regex pattern for tool/subagent matching | | command | Shell command to execute | | once | Boolean, true for run-once hooks (e.g., SessionStart) | | timeout | Optional, milliseconds |

Environment Variables

| Variable | Available In | |----------|--------------| | $CLAUDE_TOOL_NAME | PreToolUse, PostToolUse | | $CLAUDE_TOOL_INPUT | PreToolUse, PostToolUse | | $CLAUDE_TOOL_OUTPUT | PostToolUse | | $CLAUDE_SUBAGENT_TYPE | SubagentStart, SubagentStop | | $CLAUDE_SUBAGENT_PROMPT | SubagentStart |

Fallback Checklist

If doc fetch fails, use: references/hooks-checklist.md

---

Agents Validation

Official Documentation

https://docs.anthropic.com/en/docs/claude-code/sub-agents

Validation Workflow

1. Read the agent markdown file
2. Spawn claude-code-guide with prompt:

`` Fetch current standards for Claude Code custom sub-agents from https://docs.anthropic.com/en/docs/claude-code/sub-agents Focus on: agent definition format, frontmatter fields, model selection, tools array, lookup priority ``

1. Spawn bulwark-standards-reviewer with agent content and fetched standards
2. Write report to logs/validations/

Key Validation Points

| Field | Requirement | |-------|-------------| | name | Required, matches filename | | description | Required, explains agent purpose | | model | Optional: haiku, sonnet, opus | | tools | Optional: array of allowed tools | | skills | Optional: array of skills to load | | File location | .claude/agents/, ~/.claude/agents/, or plugin agents/ |

Agent Lookup Priority

1. CLI flag (--agent)
2. .claude/agents/ (project)
3. ~/.claude/agents/ (user)
4. Plugin agents/ directory
5. Built-in agents

Fallback Checklist

If doc fetch fails, use: references/agents-checklist.md

---

Commands Validation

Official Documentation

https://docs.anthropic.com/en/docs/claude-code/skills (commands merged with skills in v2.1.3)

Validation Workflow

1. Read the command file
2. Spawn claude-code-guide with prompt:

`` Fetch current standards for Claude Code commands/skills from https://docs.anthropic.com/en/docs/claude-code/skills Focus on: command invocation, argument passing ($ARGUMENTS, $1, $2), user-invocable field Note: Commands and skills merged in v2.1.3 ``

1. Spawn bulwark-standards-reviewer with command content and fetched standards
2. Write report to logs/validations/

Key Validation Points

| Aspect | Requirement | |--------|-------------| | Invocation | /skill-name arg1 arg2 | | Arguments | $ARGUMENTS (all), $1/$2 (positional) | | Environment | ${ENV_VAR} for environment variables | | Visibility | user-invocable: true for / menu |

Fallback Checklist

If doc fetch fails, use: references/commands-checklist.md

---

MCP Validation

Official Documentation

https://docs.anthropic.com/en/docs/claude-code/mcp

Validation Workflow

1. Read MCP server configuration
2. Spawn claude-code-guide with prompt:

`` Fetch current standards for Claude Code MCP servers from https://docs.anthropic.com/en/docs/claude-code/mcp Focus on: server configuration, tool definitions, transport types, security considerations ``

1. Spawn bulwark-standards-reviewer with MCP content and fetched standards
2. Write report to logs/validations/

Key Validation Points

| Aspect | Requirement | |--------|-------------| | Configuration | Valid JSON in .claude/mcp.json | | Transport | stdio, http, or sse | | Tools | Properly defined tool schemas | | Security | No exposed secrets, proper permissions |

Fallback Checklist

If doc fetch fails, use: references/mcp-checklist.md

---

Plugins Validation

Official Documentation

https://docs.anthropic.com/en/docs/claude-code/plugins

Validation Workflow

1. Read plugin manifest and structure
2. Spawn claude-code-guide with prompt:

`` Fetch current standards for Claude Code plugins from https://docs.anthropic.com/en/docs/claude-code/plugins Focus on: plugin.json manifest, directory structure, registration, flat skills directory ``

1. Spawn bulwark-standards-reviewer with plugin content and fetched standards
2. Write report to logs/validations/

Key Validation Points

| Aspect | Requirement | |--------|-------------| | Manifest | .claude-plugin/plugin.json | | Structure | Flat directories at root (skills/, agents/, hooks/) | | Registration | All components listed in manifest | | Naming | Plugin name matches directory |

Directory Structure

plugin-name/
├── .claude-plugin/
│   └── plugin.json          # ONLY manifest here
├── agents/                  # At root, NOT in .claude-plugin/
├── skills/                  # At root, NOT in .claude-plugin/
└── hooks/                   # At root, NOT in .claude-plugin/

Fallback Checklist

If doc fetch fails, use: references/plugins-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

1. 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/)

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

…

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [ashaykubal](https://github.com/ashaykubal)
- **Source:** [ashaykubal/essential-agents-skills](https://github.com/ashaykubal/essential-agents-skills)
- **License:** MIT

Install and usage instructions live in the source repository linked above.