description Use when a Unity 6.3 game is slow or stutters: low fps, frame spikes, hitches when entering areas or on first effects, GC spikes, too many draw calls or SetPass calls, CPU vs GPU bound ...

A guide for Claude (or any coding agent) working in a Unity project. It covers how to drive the open Unity Editor from the terminal, build and edit prefabs and scenes with C# scripts, enter Play mode ...