Muses-Bench

Every agent framework assumes one user giving instructions, but in real team workflows agents have multiple bosses with conflicting goals, private information, and different authority levels. Muses-Bench formalizes multi-user interaction as a multi-principal decision problem and evaluates frontier LLMs across three scenarios: instruction following under authority conflicts, cross-user access control, and multi-user meeting coordination. Gemini-3-Pro tops the leaderboard at just 85.6% average, and no model exceeds 64.8% on meeting coordination. Privacy-utility tradeoffs are brutal: Grok-3-Mini scores 99.6% on privacy but collapses to 60.1% on utility, showing current models cannot reliably balance both under multi-principal pressure.