Teaching agents product design at Vercel

This post introduces the 'product-design' skill for Vercel Agent, which provides coding agents with context behind product and codebase decisions. It details the skill's structure, including references for product judgment, interface quality, resilience, copy, patterns, and exemplars. The post outlines the skill's request modes (shape, implement, review, copy, harden) and the workflow for using it, emphasizing the importance of understanding the 'why' behind product decisions, not just the 'what'. It also describes how the skill routes to canonical sources and specific references based on the task and surface.