After the web-search and document-analysis subagents complete their tasks, the coordinator needs to spawn the...

Option B follows the Claude Agent SDK’s default context-isolation model. A newly spawned subagent receives a fresh context window and does not automatically inherit the parent’s conversation history or previous tool results. The coordinator must therefore include the information required for synthesis directly in the spawning prompt, preferably using clearly separated structured sections for web findings, document findings, source metadata, conflicts, and unresolved questions.

Anthropic’s official SDK subagent documentation states that the Agent tool’s prompt string is the content passed from the parent to the new subagent. It specifically advises including required file paths, errors, and decisions in that prompt because parent context is not inherited.

Option A could work only if the application had deliberately implemented and authorized such a shared-memory architecture. The question establishes no such mechanism, and reference identifiers alone provide no evidence to the subagent. Option C introduces a callback protocol that is unnecessary for a normal handoff. Option D is incorrect because subagent isolation expressly prevents automatic inheritance. “Complete findings” means the complete evidence needed for synthesis, not every intermediate search trace or irrelevant tool result.

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