Creating Diagrams with an Excalidraw Agent Skill and Excalidraw MCP

Using Excalidraw via MCP with GitHub Copilot in VS Code to generate architecture diagrams from natural language prompts. The setup combines an Excalidraw MCP server (giving Copilot a live drawing surface) with a custom agent skill that enforces layout rules, consistent colors, readable labels, and grouping conventions. Three real-world examples are shown: an Azure Front Door architecture flow, a GitHub Actions Terraform deployment pipeline with OIDC across dev/prod environments, and an OAuth 2.0 PKCE sequence diagram. The core argument is that keeping diagramming inside the editor workflow makes diagrams more likely to be created, kept current, and useful — rather than becoming static documentation that drifts.