skill-creator

What this skill does

## Core Principles
**Concise is key.** The context window is a shared resource between the system prompt, skills, conversation history, and your reasoning. Every line in a SKILL.md competes with everything else. Only add what you don't already know — don't document tool parameters visible in the system prompt, don't prescribe step-by-step workflows for things you can figure out. Focus on domain knowledge, interpretation guides, decision frameworks, and gotchas.

**Progressive disclosure.** Skills load in three levels:
1. **Always in context** — name, emoji, and description appear in `<available_skills>` in every conversation. This is how you decide which skill to activate. The description must be a strong trigger.
2. **On activation** — the full SKILL.md body is loaded via `read_file` when you decide the skill is relevant. This is where workflow, guidelines, and decision trees live.
3. **On demand** — scripts/, references/, and assets/ are only loaded when explicitly needed. Heavy content goes here, not in the body.

This means: keep the SKILL.md body lean (< 500 lines). Put detailed API docs in `references/`. Put automation in `scripts/`. The body should be what you need to *start working*, not an encyclopedia.

**Degrees of freedom.** Match instruction specificity to task fragility:

- **High freedom** (text guidance) — When multiple approaches are valid. Write natural language explaining WHAT and WHY, not step-by-step HOW. Example: "Check funding rates and social sentiment to gauge market mood."
- **Medium freedom** (pseudocode + params) — When a preferred pattern exists but details can vary. Describe the approach with key parameters. Example: "Use RSI with period 14, buy below 30, sell above 70."
- **Low freedom** (scripts in `scripts/`) — When operations are fragile, require exact syntax, or are repetitive boilerplate. Put the code in standalone scripts that get executed, not loaded into context. Example: Chart rendering with exact color codes and API calls.

Default assumption: you are already smart. Only add context you don't already have.

## Anatomy of a Skill
```
my-skill/
├── SKILL.md          # Required: Frontmatter + instructions
├── scripts/          # Optional: Executable code (low freedom)
│   └── render.py     #   Run via bash, not loaded into context
├── references/       # Optional: Docs loaded on demand (medium freedom)
│   └── api-guide.md  #   Loaded via read_file when needed
└── assets/           # Optional: Templates, images, data files
    └── template.json #   NOT loaded into context, used in output
```

**When to use each:**

| Directory | Loaded into context? | Use for |
|-----------|---------------------|---------|
| SKILL.md body | On activation | Core workflow, decision trees, gotchas |
| `scripts/` | Never (executed) | Fragile operations, exact syntax, boilerplate |
| `references/` | On demand | Detailed API docs, long guides, lookup tables |
| `assets/` | Never | Templates, images, data files used in output |

## Creating a Skill
### Step 1: Understand the Request

Before scaffolding, understand what you're building:

- **What capability?** API integration, workflow automation, knowledge domain?
- **What triggers it?** When should the agent activate this skill? (This becomes the description.)
- **What freedom level?** Can the agent improvise, or does it need exact scripts?
- **What dependencies?** API keys, binaries, Python packages?

Examples:
- "I want to generate charts" → charting skill with scripts (low freedom rendering)
- "Help me think about trading strategies" → knowledge skill (high freedom, conversational)
- "Integrate with Binance API" → API skill with env requirements and reference docs

### Step 2: Scaffold

Use the init script:

```bash
python skills/skill-creator/scripts/init_skill.py my-new-skill --path ./workspace/skills
```

With resource directories:
```bash
python skills/skill-creator/scripts/init_skill.py api-helper --path ./workspace/skills --resources scripts,references
```

With example files:
```bash
python skills/skill-creator/scripts/init_skill.py my-skill --path ./workspace/skills --resources scripts --examples
```

### Step 3: Plan Reusable Contents

Before writing, decide what goes where:

- **SKILL.md body**: Core instructions the agent needs every time this skill activates. Decision trees, interpretation guides, "when to do X vs Y" logic.
- **scripts/**: Any code that must run exactly as written — API calls with specific auth, rendering with exact formats, data processing pipelines.
- **references/**: Detailed docs the agent might need occasionally — full API endpoint lists, schema definitions, troubleshooting guides.
- **assets/**: Output templates, images, config files that the agent copies/modifies for output.

### Step 4: Write the SKILL.md

Plan the content first — frontmatter trigger, body structure, freedom level. Then:

1. **Frontmatter** — Update description (CRITICAL trigger), add requirements, set emoji
2. **Body** — Write for the agent, not the user. Short paragraphs over bullet walls. Opinions over hedging.

Design patterns for the body:

- **Workflow-based** — Step-by-step process (charting: fetch data → configure chart → render → serve)
- **Task-based** — Organized by what the user might ask (trading: "analyze a coin" / "compare strategies" / "check sentiment")
- **Reference/guidelines** — Rules and frameworks (strategy: core truths, conversation style, when to pull data)
- **Capabilities-based** — Organized by what the skill can do (market-data: price tools / derivatives tools / social tools)

### Step 5: Create / Update via `skill_manage`

**`skill_manage` is the primary workflow** — it validates frontmatter, runs a security scan, and auto-reloads the cache. Do NOT use `write_file` as the main path.

**Creating a new skill:**
```python
skill_manage(action="create", name="my-skill", content="---\nname: my-skill\n...")
```

**Patching an existing skill (preferred for targeted changes):**
```python
# Always read_file first to get exact whitespace/content
skill_manage(action="patch", name="my-skill", old_string="exact old text", new_string="new text")
```

**Full rewrite of existing skill:**
```python
skill_manage(action="edit", name="my-skill", content="---\nname: my-skill\n...")
```

⚠️ **Known gotchas:**
- `create` errors if skill already exists → use `edit` or `patch` instead.
- `edit`/`patch` errors if skill does NOT exist → use `create` first.
- `patch` requires exact `old_string` match (whitespace included) → always `read_file` before patching.
- `execute()` must accept `**kwargs` — if you see `unexpected keyword argument 'action'`, it's a bug in the tool implementation (fix: `def execute(self, **kwargs)`).

**Fallback only** — if `skill_manage` is unavailable, use `write_file` + `skill_refresh()` manually.

### Step 6: Validate

```bash
python skills/skill-creator/scripts/validate_skill.py ./workspace/skills/my-new-skill
```

After `skill_manage`, validate is optional (auto-reloaded), but run it to catch schema issues early.

## Frontmatter Format
The frontmatter uses `metadata.starchild` for Star Child-specific fields:

```yaml
---
name: skill-name
version: 1.0.0
description: "What this skill does. Use when [specific trigger scenarios]."

metadata:
  starchild:
    emoji: "🔧"
    skillKey: skill-name
    requires:
      env: [API_KEY_NAME]
      bins: [python]
      anyBins: [curl, wget]
    install:
      - kind: pip
        package: pandas
      - kind: apt
        package: curl
        bins: [curl]

user-invocable: true
disable-model-invocation: false
---
```

**Field reference:**

| Field | Location | Required | Purpose |
|-------|----------|----------|---------|
| `name` | top-level | Yes | Skill identifier (lowercase hyphen-case) |
| `version` | top-level | Yes | Semantic version (e.g. `1.0.0`). Required for publishing. Always include. |
| `description` | top-level | Yes | Trigger text — when should the agent use this? |
| `emoji` | `metadata.starchild`