If you're doing automated profiling with Xcode's Instruments or need to collect performance traces in CI/CD without spinning up the GUI, this is your reference. It covers xctrace, the command line tool that powers Instruments.app, with practical examples for CPU profiling, headless trace collection, and XML export for programmatic analysis. The skill targets Xcode 12+ environments and was tested with Xcode 26.2. It's part of charleswiltgen's axiom collection, which has picked up solid traction with 945 stars and 176 installs. Straightforward documentation for a tool that's powerful but not exactly well documented by Apple.
npx skills add https://github.com/charleswiltgen/axiom --skill axiom-xctrace-ref