RAGOO is an on-device AI assistant designed for hands-free interaction with surgical navigation systems. It enables surgeons to control navigation functions, display anatomical structures, check distances and angles, and access patient-specific surgical information through natural-language voice commands. RAGOO combines speech recognition, contextual intent interpretation, retrieval-augmented generation (RAG), real-time tracking data, and action guardrails that validate commands before execution. Conventional workflows often require direct touchscreen operation or assistance from other personnel, adding interaction steps and communication handoffs. RAGOO instead connects spoken requests to permitted navigation functions and targets response times of less than 0.5 seconds for UI control and distance-calculation tasks. This approach reduces direct equipment interaction and supports more immediate access to navigation information while keeping clinical judgement with the surgeon. Its software architecture supports integration with surgical navigation platforms and future clinical modules.