Overview
Long autonomous tasks create idle time for the user and can cause the main thread to accumulate excessive context. Parallel work addresses both problems. Independent workers finish closer to the duration of the longest branch rather than the sum of all branches.
Quality can improve for a second reason: different agents can focus on different aspects of the same problem. Instead of asking one agent to remember every evaluation dimension while it searches, the orchestrator gives each worker a narrower objective. The final result can therefore cover more of the problem without forcing one context window to carry the full burden.