Writing Skills

REQUIRED BACKGROUND: Read ed3d-extending-claude:writing-claude-directives for foundational guidance on token efficiency, discovery optimization, and compliance techniques. This skill focuses on TDD methodology specific to skill creation.

Core Principle

Writing skills IS Test-Driven Development applied to process documentation.

Write test cases (pressure scenarios), watch them fail (baseline behavior), write the skill, watch tests pass, refactor (close loopholes).

Iron Law: No skill without a failing test first. Same as TDD for code.

TDD Mapping

When to Create a Skill

Create when:

• Technique wasn’t intuitively obvious
• You’d reference this across projects
• Pattern applies broadly
• Others would benefit

Don’t create for:

• One-off solutions
• Standard practices documented elsewhere
• Project-specific conventions (use CLAUDE.md)

Skill Types

Technique: Concrete method with steps (condition-based-waiting, root-cause-tracing)

Pattern: Mental model for problems (flatten-with-flags, test-invariants)

Reference: API docs, syntax guides, tool documentation

Directory Structure

skills/
  skill-name/
    SKILL.md              # Main reference (required)
    supporting-file.*     # Only if needed

Separate files for: Heavy reference (100+ lines), reusable tools/scripts

Keep inline: Principles, code patterns (<50 lines), everything else

SKILL.md Template

---
name: Skill-Name-With-Hyphens
description: Use when [triggers/symptoms] - [what it does, third person]
---

# Skill Name

## Overview
Core principle in 1-2 sentences.

## When to Use
Symptoms and use cases. When NOT to use.

## Core Pattern
Before/after comparison or key technique.

## Quick Reference
Table or bullets for scanning.

## Common Mistakes
What goes wrong + fixes.

RED-GREEN-REFACTOR Cycle

RED: Baseline Test

Run pressure scenario WITHOUT skill:

1. Create combined pressures (time + sunk cost + exhaustion)
2. Document exact violations and rationalizations verbatim
3. Identify failure patterns

GREEN: Write Minimal Skill

1. Address specific baseline failures identified in RED
2. Run scenarios WITH skill
3. Verify compliance

REFACTOR: Close Loopholes

1. Find NEW rationalizations from testing
2. Add explicit counters
3. Re-test until bulletproof

REQUIRED: Use ed3d-extending-claude:testing-skills-with-subagents for complete methodology.

Testing by Skill Type

Common Rationalizations to Block

All mean: Test before deploying.

Anti-Patterns

• Narrative example: “In session 2025-10-03, we found…” (too specific, not reusable)
• Multi-language dilution: example-js.js, example-py.py (mediocre quality, maintenance burden)
• Code in flowcharts: Can’t copy-paste, hard to read
• Generic labels: helper1, step3 (labels need semantic meaning)

Skill Creation Checklist

IMPORTANT: Use TaskCreate to track each item (or TodoWrite in older Claude Code versions).

RED Phase:

• Create pressure scenarios (3+ combined pressures for discipline skills)
• Run WITHOUT skill – document baseline failures verbatim
• Identify rationalization patterns

GREEN Phase:

• Name uses letters, numbers, hyphens only
• Description starts with “Use when…”, third person
• Address specific baseline failures
• One excellent example (not multi-language)
• Run WITH skill – verify compliance

REFACTOR Phase:

• Identify new rationalizations
• Add explicit counters
• Re-test until bulletproof

Deployment:

• Commit and push
• Consider contributing via PR