Option C converts the linear pipeline into a controlled iterative research loop. The document-analysis agent is best positioned to identify precisely what the retrieved evidence fails to answer. It should return structured gaps containing the missing question, evidence already examined, preferred source characteristics, and the coverage criterion that remains unsatisfied. The coordinator can then issue focused searches and resubmit the new material for analysis.

Anthropic’s multi-agent research architecture uses a lead agent to decompose work, coordinate research agents, assess returned information, and continue investigation when further evidence is required. The guidance also stresses clear objectives, output formats, source requirements, and task boundaries to prevent gaps and duplicated work.

Option A may improve initial coverage but cannot anticipate every deficiency revealed only after sources are examined. Option B documents incompleteness rather than correcting it. Option D retrieves more information but does not ensure that the new evidence is analyzed and tested against the original gap. The loop in Option C establishes an explicit completion condition and preserves specialization: analysis identifies the gap, the coordinator orchestrates, search agents retrieve evidence, and analysis verifies whether the gap has actually been closed.

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