skill-forge

name

skill-forge

description

Orchestrates ALL skill development — MANDATORY gate BEFORE writing or editing any SKILL.md file. Invoke FIRST when building, validating, improving, or refactoring skills. Supersedes skill-creator. Unified 6-step workflow with automated validation, CSO scoring, and subagent testing. Triggers on 'create skill', 'new skill', 'validate skill', 'check skill quality', 'improve skill discovery', 'check this skill', 'write SKILL.md', 'edit SKILL.md', 'update skill description', 'can I share this', 'scan for sharing'. (user)

Skill Forge

Unified skill development toolkit. Supersedes skill-creator — combines its creation process with quality validation, description optimization, and testing.

Iron Law: Skills must be discovered to be useful. The description is everything.

When to Use

• BEFORE writing any SKILL.md file
• When creating a new skill from scratch
• When improving an existing skill's discovery rate
• When validating skill quality before deployment
• When scanning a skill/repo before sharing publicly

When NOT to Use

• One-off instructions (put in CLAUDE.md instead)
• Simple tool usage Claude already knows
• Tasks that don't repeat across sessions

Rationalizations to Block

Claude frequently skips this skill by reasoning:

• "I already know how to create skills" — You know the generic pattern. This skill adds CSO scoring, lint, and project-specific conventions you don't have in training.
• "skill-creator covers this" — skill-forge supersedes skill-creator. Use forge, not creator.
• "I'll validate later" — Validation after writing is expensive rework. Forge-first, always.
• "This is just a small edit to an existing skill" — Small edits to descriptions are exactly where CSO scoring matters most.

Quick Start

# 1. Initialize new skill
scripts/init_skill.py my-skill --path ~/.claude/skills

# 2. Edit SKILL.md (see Workflow below)

# 3. Lint for structure issues
scripts/lint_skill.py ~/.claude/skills/my-skill

# 4. Score description quality (CSO)
scripts/score_description.py ~/.claude/skills/my-skill

# 5. Test with subagent (optional but recommended)
scripts/test_skill.py ~/.claude/skills/my-skill

# 6. Package for distribution (optional)
scripts/package_skill.py ~/.claude/skills/my-skill

Workflow: 6-Step Process

Step 1: Understand with Concrete Examples

Goal: Know exactly how the skill will be used before building.

Questions to answer:

• "What would a user say that should trigger this skill?"
• "Can you give examples of how this skill would be used?"
• "What should happen after the skill triggers?"

Exit criterion: Clear list of trigger phrases and expected behaviors.

Step 2: Plan Reusable Contents

Analyze each example to identify:

Content Type	When to Include	Example
scripts/	Same code rewritten repeatedly	rotate_pdf.py
references/	Documentation Claude should reference	schema.md
assets/	Files used in output (not loaded)	template.pptx

Exit criterion: List of scripts/references/assets to create.

Step 3: Initialize

scripts/init_skill.py <skill-name> --path <directory>

Creates SKILL.md template, example scripts/references/assets. Delete unneeded files.

Step 4: Edit

Order matters:

1. Create scripts/references/assets first
2. Test scripts actually work
3. Write SKILL.md last (it references the resources)

SKILL.md Structure

---
name: kebab-case-name
description: [See CSO Patterns below]
---

Body sections:

• Core principle / Iron Law
• When to Use / When NOT to Use
• Workflow with success criteria
• Anti-patterns
• Quick reference
• Integration with other skills

Naming

• Lowercase letters, numbers, hyphens only. Max 64 chars.
• Must match directory name exactly.
• Gerund or capability form preferred.

Good	Bad	Why
systematic-debugging	debug	Verb, not capability
workspace-fluency	utils	Generic, no information
test-driven-development	pdf-helper	"helper" is meaningless
desired-outcomes	my-skill	Doesn't describe purpose

CSO Patterns (Critical)

The description determines discovery. Pattern: [ACTION TYPE] + [SPECIFIC TRIGGER] + [METHOD/VALUE PREVIEW]

Best: MANDATORY gate with BEFORE condition

description: MANDATORY gate before writing any SKILL.md file. Invoke FIRST when building new skills - provides structure, naming, and quality checklist that MUST be validated before deployment.

Why: "MANDATORY gate" not optional, "before writing" timing, "FIRST" positioning, "MUST" imperative.

Good: Specific trigger with method preview

description: Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes - four-phase framework (root cause, pattern analysis, hypothesis testing, implementation) ensures understanding before solutions.

Why: specific trigger + timing gate + method preview + value statement.

Good: Natural phrase triggers

description: Coach on outcome quality. Triggers on 'check my outcomes', 'is this a good outcome', 'review my Todoist' when discussing strategic work.

Why: explicit phrases in quotes, context qualifier.

Bad patterns to avoid:

Pattern	Problem	Fix
"Helps with..."	Vague, no trigger	Specific phrases in quotes
"Use when creating..."	Too generic	"MANDATORY gate before..."
No timing condition	Optional invocation	Add BEFORE/FIRST/MANDATORY
Generic actions	Claude "knows" without loading	Domain-specific phrases
Command doesn't name skill	Not discoverable	"Invoke the name skill"

Run scripts/score_description.py to validate. See references/cso-guide.md for full guidance.

Step 5: Validate

# Automated lint (structure, naming, frontmatter)
scripts/lint_skill.py <skill-path>

# CSO score (description quality)
scripts/score_description.py <skill-path>

# Subagent test (discovery + workflow)
scripts/test_skill.py <skill-path>

All checks must pass before Step 6.

Step 6: Package (Optional)

scripts/package_skill.py <skill-path> [output-dir]

Creates .skill file (zip format) for distribution.

Quality Checklist

Structure

• SKILL.md under 500 lines
• Name matches directory exactly (kebab-case)
• Name is gerund/capability form
• Description is third-person ("Orchestrates", not "Use")
• Description includes trigger AND method AND timing
• Description ends with (user) tag for user-defined skills
• References one level deep from SKILL.md
• YAML frontmatter has name and description only

Content

• No time-sensitive information
• Consistent terminology throughout
• Concrete examples, not abstract rules
• Configuration values justified
• Error handling documented
• Dependencies explicitly listed
• Anti-patterns section present

Workflow

• Clear phases/steps with success criteria
• When to Use AND When NOT to Use sections
• Integration points with other skills explicit
• Verification/validation included
• Quick reference for common operations

Discovery

• BEFORE/MANDATORY/FIRST patterns used appropriately
• Trigger phrases are natural language in quotes
• Context qualifiers included (when appropriate)
• Method preview gives Claude enough to decide relevance
• If paired with command, command names the skill explicitly

Skill Patterns

See references/skill-patterns.md for full taxonomy. Summary:

Type	Key Feature	Description Pattern
Process	Phases with gates	BEFORE condition
Fluency	Tool best practices	Specific trigger phrases
Coaching	Quality criteria	Natural language triggers
Gate	Checklist validation	MANDATORY language
Skill+CLI	Orchestrates CLI tool	BEFORE any cli command

Skill+CLI Pattern (Most Powerful)

When skill orchestrates a CLI tool. See references/skill-cli-pattern.md for full template.

# {skill-name}
Orchestrates {domain} using `{cli}` command.
## CLI Reference
## Workflows
## When Skill Extends CLI (coaching, quality criteria)
## Error Recovery

What High-Invocation Skills Share

1. BEFORE conditions in description
2. Specific trigger phrases in quotes
3. Method preview that's actionable
4. Clear anti-patterns that catch mistakes
5. Integration points that compose with other skills

What Low-Invocation Skills Suffer From

1. Generic "Use when..." descriptions
2. Vague propositions ("helps with", "guides", "assists")
3. Missing timing gates
4. Documenting what Claude already knows

Anti-Patterns

Discovery Failures

Anti-Pattern	Symptom	Fix
"Use when creating..."	Claude bypasses skill	"MANDATORY gate before..."
"Helps with..."	Never invoked	Specific trigger phrases
No timing gate	Optional invocation	Add BEFORE/FIRST
Generic actions	Claude "knows" without loading	Domain-specific phrases

Structure Failures

Anti-Pattern	Symptom	Fix
SKILL.md > 500 lines	Token bloat	Split into references/
Name doesn't match dir	Skill not found	Keep synchronized
Deeply nested refs	Discovery fails	One level deep max

Content Failures

Anti-Pattern	Symptom	Fix
Explaining known things	Wastes tokens	Domain-specific only
Magic constants	Unclear reasoning	Justify all values
Many options, no default	Analysis paralysis	Recommend one path

Quick Reference

Minimum Viable Skill

---
name: kebab-case-name
description: [TIMING] + [TRIGGER] + [METHOD/VALUE]. Triggers on 'phrase1', 'phrase2'. (user)
---

# Skill Title

[Core principle]

## When to Use
[Specific triggers with examples]

## When NOT to Use
[Clear boundaries]

## Workflow
[Steps with success criteria]

## Anti-Patterns
[What to avoid with fixes]

Files to Include

File	Purpose	When Required
SKILL.md	Core instructions	Always
references/*.md	Detailed guides	When SKILL.md > 500 lines
scripts/*.py	Utility scripts	When deterministic code needed
assets/*	Output templates	When Claude uses files in output

Before Sharing

Run the sharing scanner:

scripts/scan.py <skill-path>
scripts/scan.py --risk high <skill-path>  # High-risk only

Detects: emails, paths with usernames, secrets, company terms. See references/sharing-scan.md for triage guidelines.

Integration

Anthropic scripts (symlinked from skill-creator):

• init_skill.py — generate template
• package_skill.py — create .skill file

Forge scripts:

• lint_skill.py — automated structure validation
• score_description.py — CSO quality scoring
• test_skill.py — subagent pressure testing
• scan.py — PII/secrets scanner for sharing
• render_graphs.py — DOT workflow diagrams to SVG

References

• references/cso-guide.md — Claude Search Optimization principles
• references/skill-cli-pattern.md — Skill+CLI template
• references/skill-patterns.md — Pattern taxonomy with examples
• references/rationalization-table.md — Common excuses to block
• references/sharing-scan.md — Sharing triage guidelines
• references/dot-graphs.md — DOT graph syntax for workflow diagrams