Option B follows the Claude Agent SDK's subagent context model. A normal subagent begins with a fresh context window and does not inherit the parent agent's conversation history or prior tool results. Anthropic's Subagents in the SDK documentation states that the information passed from parent to subagent is the spawning tool's prompt string; required file paths, decisions, errors, or findings must therefore be included in that prompt. In this scenario, the coordinator should supply both agents' relevant findings, source metadata, and explicit synthesis instructions. ''Complete findings'' means the full required result artifacts, not every intermediate search trace. Option C incorrectly assumes automatic context inheritance. Option A introduces callbacks that are neither necessary nor the standard handoff mechanism. Option D can be a valid custom architecture when a shared store has deliberately been implemented, but the question does not establish such infrastructure, and identifiers alone do not give the subagent information. The prompt should use clear sections or structured objects to distinguish web findings, document findings, sources, unresolved conflicts, and expected output. This preserves context isolation while providing everything the synthesis task actually requires.

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