The rule. Hand the coding agent your design decisions as persistent, versioned context (project rules plus the design file over MCP), never as a one-off prompt.
Why. Large language models do not retain memory between completions, which is Cursor's own stated reason rules exist: they provide "persistent, reusable context at the prompt level," included at the start of the model context when applied (Cursor, n.d.-a). Project rules live in .cursor/rules as version-controlled files, scoped by path patterns, and Cursor recommends them for standardizing style or architecture decisions, which is a fair description of what a design system is (Cursor, n.d.-a). Cursor also speaks the Model Context Protocol, which "enables Cursor to connect to external tools and data sources," so the design file itself can arrive as structured context instead of a screenshot (Cursor, n.d.-b).
Seen in the wild. Figma's official MCP server pulls "variables, components, and layout data" straight into supported editors, Cursor included, with Code Connect reusing your actual components to keep generated code consistent with your codebase (Figma, n.d.).
Verified as of 2026-08-23 against current Cursor and Figma documentation.