Production monitoring shows that follow-up queries such as “summarize what we learned about market trends”...

Option C avoids an unnecessary agent boundary. The coordinator already possesses the accumulated findings and can perform a straightforward summary without serializing, transferring, and reprocessing more than 80,000 tokens in another context window. Subagents should be reserved for work that requires isolated context, specialized instructions, separate tools, or an independent analytical process.

Anthropic’s current prompting guidance advises using subagents for independent workstreams and parallel or context-isolated tasks, while handling simpler tasks directly. Anthropic also notes that excessive subagent use creates unnecessary cost and latency.

Option A generates multiple summaries speculatively, consuming resources even if they are never requested and creating cache-invalidation complexity whenever findings change. Option B may reduce repeated input-token cost, but it does not eliminate subagent startup, message processing, or the unnecessary orchestration round trip. Option D introduces an iterative request protocol that will likely increase latency further. Direct coordinator summarization uses information already available in active context and therefore provides the smallest architectural change, lowest token-transfer overhead, and fastest response while preserving subagent synthesis for genuinely complex comparative or cross-source analysis.

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