Protocols for driving Onshape CAD via the onshape-mcp plugin. Render-first and entity-first workflows, unit + coordinate conventions, iteration discipline, when to reach for FeatureScript, and the gotchas (REMOVE-on-face auto-flip, Variable Studios as separate elements, deterministic ID remapping). Load before building anything in Onshape โ the plugin's MCP tool surface makes more sense with this doc in context.
Look at an engineering reference image (drawing, iso render, photo) and produce a structured feature decomposition BEFORE building anything in Onshape. Output is a feature tree the user can review and the build phase can execute against. Use this whenever the user gives you a reference image and asks you to model it. Skip if the user has already described the part in plain text.