More agents don't mean higher performance. There is a coordination bottleneck to consider. Not to mention the unnecessary costs. So how many of a multi-agent team's actions actually help it finish the task? In this AgentWorld paper, fewer than a third. AgentWorld puts 3 to 20 LLM agents with different roles into a game sandbox for tasks that run 50+ rounds. Agents can't see each other's internal state, so they have to coordinate through messages and shared plans. Gemini 3 Flash has the…