skill-creator

Scaffold new skills with valid frontmatter, directory layout, and a starter SKILL.md. Use when building a new reusable workflow or wrapping a new API (e.g. create a kalshi skill, scaffold an API helper, start a charting skill).

By starchild-ai-agent · 7,729 installs

npx skills add starchild-ai-agent/official-skills --skill skill-creator

Source repository · Upstream listing

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 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: With resource directories: With example files: 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: Patching an existing skill (preferred for targeted changes): Full rewrite of existing skill: ⚠️ 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 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: 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 No Display emoji skillKey metadata.starchild No Dedup key requires.env metadata.starchild No Required env vars requires.bins metadata.starchild No Required binaries (ALL must exist) requires.anyBins metadata.starchild No Required binaries (ANY one) install metadata.starchild No How to install deps (pip, apt, npm, etc.) user invocable top level No Can user trigger via /command (default: true) disable model invocation top level No Hide from <available skills (default: false) On Chain Skills — Wallet Policy Prerequisite If the skill involves any on chain operations (sending transactions, token approvals, swaps, bridging, signing, deposits, withdrawals, smart contract interactions), add a Prerequisites section near the top of the SKILL.md: This ensures the agent proposes a wallet policy before attempting any transaction. Without it, the first transaction will fail with a policy violation. What NOT to Include README.md — The SKILL.md IS the readme. Don't duplicate. CHANGELOG.md — Skills aren't versioned packages. Docs the agent already has — Don't repeat tool descriptions from the system prompt. Step by step for simple tasks — The agent can figure out "read a file then process it." Generic programming advice — "Use error handling" is noise. Specific gotchas are signal. Best Practices 1. Description is the trigger. This is how the agent decides to activate your skill. Include "Use when..." with specific scenarios. Bad: "Trading utilities." Good: "Test trading strategies against real historical data. Use when a strategy needs validation or before committing to a trade approach." 2. Write for the agent, not the user. The skill is instructions for the AI. Use direct language: "You generate charts" not "This skill can be used to generate charts." 3. Scripts execute without loading. Good for large automation. The agent reads the script only when it needs to customize, keeping context clean. 4. Don't duplicate the system prompt. The agent already sees tool names and descriptions. Focus on knowledge it doesn't have: interpretation guides, decision trees, domain specific gotchas. 5. Request credentials last. Design the skill first, then ask the user for API keys. 6. Always validate before refreshing — run validate skill.py to catch issues early.