Skillify

Generate a SKILL.md file for an npm package, making it discoverable and usable by AI agents.

When to Use

• Adding agent documentation to an npm package
• Making a library AI-agent friendly
• Creating a skill from existing CLI tool
• Preparing a package for the Agent Skills ecosystem

Quick Start

Use the npm CLI tool:

bash
npx skill-gen .                    # Current directory
npx skill-gen ~/path/to/package    # Local package
npx skill-gen . --stdout           # Preview output

Or invoke manually via /skillify <path>.

Process

Step 1: Gather Package Information

Read these files (in order of importance):

1. package.json (required)

• name → skill name (kebab-case)
• description → base for skill description
• bin → CLI commands available
• main/exports → API entry points
• keywords → trigger words

1. README.md (if exists)

• Usage examples
• API documentation
• Installation instructions

1. CLI entry point (if bin exists)

• Parse for --help output
• Extract flags and commands

1. Main module (if main/exports exists)

• Exported functions
• JSDoc comments
• Type definitions

Step 2: Analyze for Agent Usage

Determine:

• What it does - core functionality in one sentence
• When to use - specific triggers/contexts
• How to use - primary usage pattern (CLI or API)
• Examples - concrete input/output pairs

Step 3: Generate SKILL.md

Follow this template:

yaml
---
name: <package-name-kebab-case>
description: <What it does>. <When to use - specific triggers>.
---

Description rules:

• Third person only ("Builds X" not "I build X")
• Under 1024 characters
• Include both WHAT and WHEN
• Use specific keywords for discovery

Body structure:

markdown
# <Package Name>

## When to Use

Invoke when you need to:
- <specific trigger 1>
- <specific trigger 2>
- <specific trigger 3>

## Quick Start

<primary usage pattern - CLI or code>

## Examples

**Example 1: <use case>**

Input:
<concrete input>

Output:
<concrete output>

## CLI Reference (if applicable)

<flags and commands>

## API Reference (if applicable)

<key exported functions>

Step 4: Write the File

Save to: <package-root>/SKILL.md

Quality Checklist

Before finalizing, verify:

• ] Description is third person
• ] Description includes WHAT and WHEN
• ] Description under 1024 characters
• ] Name is kebab-case, lowercase
• ] Examples are concrete (not abstract)
• ] Body under 500 lines
• ] No time-sensitive information
• ] Consistent terminology

Description Formula

<Verb>s <object> [details]. Use when <trigger1>, <trigger2>, or <trigger3>.

Good examples:

yaml
description: Builds Bitcoin Taproot transactions from inputs and outputs. Use when creating P2TR transactions, spending UTXOs, or working with Taproot addresses.

yaml
description: Broadcasts signed Bitcoin transactions to the network. Use when sending transactions to mempool, publishing to testnet4, or checking broadcast status.

Bad examples:

yaml
description: Helps with Bitcoin stuff.  # Too vague
description: I can build transactions.  # Wrong POV
description: A library for transactions.  # No "when to use"

Naming Convention

Convert package name to kebab-case:

| package.json name | SKILL.md name | |-------------------|---------------| | btctx | btctx | | sendTx | send-tx | | BitcoinBuilder | bitcoin-builder | | @scope/pkg | pkg (drop scope) |

Example Output

For a package like btctx:

yaml
---
name: btctx
description: Builds Bitcoin Taproot (P2TR) transactions from UTXOs. Use when creating Bitcoin transactions, spending Taproot outputs, or building raw transaction hex.
---

# btctx

## When to Use

Invoke when you need to:
- Build a Bitcoin transaction from UTXOs
- Create Taproot (P2TR) outputs
- Generate signed transaction hex for broadcasting

## Quick Start

import { buildTx } from 'btctx';

const { hex, txid } = await buildTx({ privateKey: '...', publicKey: '...', txid: '<input-txid>', vout: 0, inputAmount: 100000, outputs: { pubkey: '<recipient>', amount: 99000 }] });

## Examples

**Example: Simple transfer**

Input:
- 100,000 sats from UTXO
- Send to one recipient

Output:
- Signed transaction hex
- Transaction ID (txid)

## API Reference

### `buildTx(options)`

Builds and signs a Taproot transaction.

Options:
- `privateKey` - 64-char hex signing key
- `publicKey` - 64-char hex x-only pubkey
- `txid` - Input transaction ID
- `vout` - Output index to spend
- `inputAmount` - Satoshis in input
- `outputs` - Array of `{ pubkey, amount }`

Returns: `{ hex, txid }`

References

• Agent Skills Specification
• Anthropic Best Practices
• GitHub: anthropics/skills