Diagram Design skill: what it does and how to install it

What it does. Selects a semantic pattern and visual type, then produces self-contained HTML files with inline SVG, branded tokens, accessible metadata and editorial layouts. It supports 45 diagram and chart types, imports .drawio, Mermaid and Excalidraw files, and checks geometry, spacing, connector routing and complexity before output.

When to use it. Use it when a visual communicates architecture, process, relationships, data or change better than prose. Do not use it for quick Unicode diagrams, simple lists, attribute-only comparisons or one-shape diagrams.