Expert Skill Creation
Transform expert knowledge into production-ready skills that combine domain expertise with system-specific understanding.
Why Skills Fail in Production
AI assistants fail not because they lack intelligence, but because they lack:
- Domain Expertise — Industry-specific rules, edge cases, unwritten conventions
- Ontology Understanding — How YOUR systems, data structures, and workflows actually work
Both are required. Domain knowledge without system context produces generic output. System knowledge without domain expertise produces structurally correct but semantically wrong results.
Workflow
Assess → Discover (Expertise + Ontology) → Design → Create → Refine → Ship
Quick Assessment
Create a skill when:
- Used 3+ times (or will be)
- Follows consistent procedure
- Saves >300 tokens per use
- Requires specialized knowledge not in Claude's training
- Must produce trusted output (not "close enough")
Don't create for: one-time tasks, basic knowledge Claude already has, rapidly changing content.
Discovery: Two Streams
Stream 1: Domain Expertise
Deep knowledge that transcends any specific company:
- Industry standards and their versions
- Professional conventions and best practices
- Edge cases only practitioners know
- Validation rules from specifications
Example (LEDES validation): LEDES 98B vs XML 2.0 formats, UTBMS code taxonomy, date format requirements, required vs optional fields.
Stream 2: Ontology Understanding
How the skill maps to specific systems and organizations:
- Company-specific policies and constraints
- Data structures and identifiers unique to the system
- Cross-references between entities (timekeepers → IDs → rates)
- Workflow states and transitions
Example (LEDES validation): Firm-specific timekeeper codes, matter numbering conventions, approved billing rates, outside counsel guideline requirements.
Discovery Questions
When starting, I'll ask about:
- Domain & Purpose — What problem? What industry standards apply?
- Ontology Requirements — What system-specific structures must the skill understand?
- Content Source — Conversation, docs, specifications, or files to distill from?
- Automation Potential — What can be deterministic (scripts)? What needs interpretation (LLM)?
- Complexity Level — Simple (SKILL.md only), Enhanced (+scripts), or Full (+resources)?
Skill Architecture
skill-name/
├── SKILL.md # Layer 1: Core (300-500 tokens)
├── scripts/ # Layer 0: Automation (0 tokens to run)
│ └── validate.py
└── resources/ # Layer 2: Details (loaded selectively)
└── ADVANCED.md
Layer 0 (Scripts): Free execution, structured JSON output
Layer 1 (SKILL.md): Loaded when triggered - keep lean
Layer 2 (Resources): Fetched only when specific section needed
Token Optimization
| Technique | Instead of | Do this | Savings |
|---|
| Scripts | 500 tokens explaining validation | python scripts/validate.py
| ~450 tokens |
| Reference | Inline schema (200 tokens) | Link to | ~185 tokens |
| Layer 2 | Everything in SKILL.md | Link to | ~750 tokens |
Description Formula
<Action> <Object> for <Purpose>. Use when <Trigger>.
Example: "Validate billing data for system migration. Use before importing invoices."
Shipping
When content is finalized:
bash
python scripts/package_skill.py skill-name 1.0
- DIRECTORY_STRUCTURE.txt (auto-generated)
- README.md with deployment instructions
- All skill files properly organized
Templates & Examples
- Minimal skill template
- Enhanced skill template
- Script template
See
for domain-specific patterns.
Quality Checklist
Before shipping:
Version: 2.2 | Target: <500 tokens Layer 1