Teaching agents product design at Vercel

What this post added

This post details the architecture and implementation of Vercel's 'product-design' skill, a system designed to provide coding agents with product design context. It outlines the repository structure for the skill, including `AGENTS.md`, `SKILL.md`, `references/` (e.g., `product-judgment.md`, `interface-quality.md`, `copy.md`), and `exemplars/`. The post elaborates on the skill's request routing modes (shape, implement, review, copy, harden) and the decision authority hierarchy. It also defines a detailed workflow for applying the skill, from setting scope and mode to loading context, modeling decisions, mapping surfaces, loading routed references, implementing, and verifying the output. The core contribution is the formalization of a system that bridges the gap between code and product design rationale for AI agents.