deep-research

Deep, multi-source, fact-checked research on a topic — fan out searches, read primary sources, adversarially verify each claim, and synthesize a cited report. Use when the user wants a thorough research report rather than a quick answer, e.g. "深度调研", "research this properly", "写一份调研报告", "帮我系统调研", "多来源核实", "give me a researched writeup", "背景调查一下". BEFORE starting, if the question is underspecified (scope, region, time window, use-case unclear), ask 2-3 clarifying questions to narrow it. For a single quick lookup use web_search directly; for a whole codebase/feature use the relevant dev skills.