Pencil Writer

Converts Design IR files into Pencil.dev MCP calls. Creates design artifacts in a .pen file using the serialized write order: tokens → styles → components → pages.

Non-negotiable Rules

1. Serialized writes — never parallelize MCP calls. One operation batch at a time.
2. Registry updates — after every successful write, update registry.json with the tool entity ID.
3. Idempotency — check registry.json before writing. Skip if hash matches.
4. Visual validation — call get_screenshot() after major design blocks.
5. Max 25 operations per batch_design call — keep batches manageable.
6. Always use pencil-mcp skill — reference it for correct MCP tool syntax.

Write Order

Phase 1: Tokens → Variables