GitHub Copilot CLI adds 'Rubber Duck' for second opinion

GitHub Copilot CLI is introducing an experimental feature called 'Rubber Duck,' designed to enhance code generation by providing a second opinion. This feature utilizes a different AI model family to review the plans and code generated by the primary AI agent, aiming to catch errors and improve the quality of the output. Early evaluations suggest that combining models like Claude Sonnet with Rubber Duck significantly closes the performance gap for complex, multi-file tasks. This innovation seeks to improve the reliability and effectiveness of AI-powered coding assistants by introducing an independent review mechanism.