Slash Command

Rules Eval

Evaluate Claude Code rules in .claude/rules/ directories for quality

Type: Slash Command
Repository: athola/claude-night-market
GitHub stars: 339
License: MIT
Repo last updated: Sep 24, 2026
Source file: plugins/abstract/commands/rules-eval.md

What Rules Eval is

Rules Eval is a slash command published in the athola/claude-night-market repository on GitHub, which has about 339 stars. The repository describes itself as: “23 Claude Code plugins: TDD enforcement hooks, git/PR workflows, spec-driven development, code review, project lifecycle, fix-from-error, maintenance automation, context optimization, research, and multi-LLM delegation. 186 skills, 128 commands, 54 agents.”

A slash command is a reusable prompt saved as a markdown file and run by typing its name after a slash. In Claude Code, custom commands have been merged into skills: a file in .claude/commands/ and a skill folder in .claude/skills/ both create the same kind of command, and existing command files keep working.

Rules Eval gives you a repeatable way to run the same instructions without retyping them, optionally with arguments.

How to install Rules Eval

Claude Code

Download rules-eval.md from the repository.
Save it to ~/.claude/commands/ (all projects) or .claude/commands/ (one project). As a skill, you can instead save it as ~/.claude/skills/<name>/SKILL.md.
Run it by typing / followed by its name.

Claude Cowork

Turn the command into a skill: create a folder with the file saved as SKILL.md and zip it.
In Customize → Skills, click +, then upload the ZIP.
Run it from any task with / and the skill name.

New to extending Cowork? Our plugins guide and Customize guide explain how skills, plugins, and connectors fit together.

Inside the source file

An excerpt from plugins/abstract/commands/rules-eval.md, shared under the repository's MIT license. Read the full file on GitHub.

Evaluate and validate Claude Code rules in .claude/rules/ directories. Checks YAML frontmatter, glob patterns, content quality, and directory organization.

Invoke Skill(abstract:rules-eval), which carries the scoring, the frontmatter and glob validations and the organization patterns.

When To Use

Use this command when you need to:

Validate rule files before deployment
Audit frontmatter for YAML errors or Cursor-specific fields
Check glob patterns for syntax and specificity issues
Assess overall rules organization and naming

When NOT To Use

Avoid this command if:

Evaluating skills - use /skills-eval instead
Evaluating hooks - use /hooks-eval instead
Validating full plugin structure - use /validate-plugin instead

Usage

# Evaluate rules in current project
/rules-eval

# Evaluate specific directory
/rules-eval .claude/rules/

# Detailed analysis with per-file breakdown
/rules-eval --detailed

# Evaluate a plugin's rules
/rules-eval plugins/conserve/.claude/rules/

Implementation

python3 ${CLAUDE_PLUGIN_ROOT}/scripts/rules_validator.py \
  "${1:-.claude/rules}" \
  ${2:+--detailed}

Related Commands

/skills-eval - Skill quality evaluation
/hooks-eval - Hook quality evaluation
/validate-plugin - Complete plugin structure validation

Related Skills

rules-eval skill (skills/rules-eval/SKILL.md) - Detailed evaluation framework
modules/frontmatter-validation.md - YAML/frontmatter checks
modules/glob-pattern-analysis.md - Glob pattern validation
modules/content-quality-metrics.md - Content quality assessment
modules/organization-patterns.md - Directory organization

Before you install

Read the whole file first. Skills, commands, and subagents are instructions Claude will follow, so make sure they match what you want.
Check which tools, scripts, or MCP servers it uses. Local servers and scripts run with your permissions.
Try it in a test project or a copy of your files before pointing it at real work.
Pin the version you tested, and review changes before updating.
Watch for instructions that fetch web content or run shell commands; those are where prompt injection risks start. See our prompt injection guide.

FAQ

What is Rules Eval?

Rules Eval is a slash command for Claude Code and Claude Cowork from the athola/claude-night-market repository on GitHub. Evaluate Claude Code rules in .claude/rules/ directories for quality

How do I install Rules Eval in Claude Code?

Download rules-eval.md from the repository. Save it to ~/.claude/commands/ (all projects) or .claude/commands/ (one project). As a skill, you can instead save it as ~/.claude/skills/<name>/SKILL.md. Run it by typing / followed by its name.

Can I use Rules Eval in Claude Cowork?

Turn the command into a skill: create a folder with the file saved as SKILL.md and zip it. In Customize → Skills, click +, then upload the ZIP. Run it from any task with / and the skill name.

Is Rules Eval safe to install?

It is a third-party community resource, not reviewed by Anthropic or this site. Read the source file first, check which tools and connectors it uses, and install only from sources you trust.

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Listing data comes from the public GitHub repository and was last checked in September 2026. Excerpts are © their authors and shared under MIT. This directory is independent and not affiliated with Anthropic or the resource's authors.