Anthropic recommends consolidating sub-agents into a single agent as newer models handle complexity
Anthropic says newer models (starting with Opus 4.5, plus Opus 5.5 and Fable 5.1) can manage complex plans in a single loop, so a primary agent that loads context and tools on demand often outperforms fleets of specialized sub-agents on quality, cost, and latency. The company published a GitHub migration kit with a step-by-step workflow and caveats — e.g., sub-agents still make sense when context-window limits, parallel tasks, or tool-selection failures arise.