Deep Research

This is the web / multi-source counterpart to research-mastery. That skill is KB-first: it answers from the project's own knowledge base and only reaches outward when the KB comes up empty. This one governs what happens once you are already out on the open web pulling from many independent sources and have to weave them into one trustworthy answer. It is a method, not a fetcher — it does not retrieve anything by itself. You supply the search and fetch tools (built-in WebSearch / WebFetch, or the runtime deep-research command); this skill tells you how to spend them and how hard to doubt what comes back.

Retrieve-vs-Answer Gate

Run this gate before you spend a single search:

1. Is the answer already in the KB or your own context? Then this is not a deep-research job — hand it to research-mastery (which checks RAG-MCP first) or just answer.
2. Is it one stable fact with a single obvious authority (a constant, a published spec value, a definition that does not move)? One targeted lookup, confirm, done. Do not open a research campaign.
3. Does it need several independent sources reconciled, or is it contested, recent, or moving? That is the case this skill exists for. Continue.

Skipping this gate is the most common failure: people fan out ten searches on a question that one source already settled, or worse, answer a contested question from memory because it "felt known."

Scale Effort to Complexity

Match the search budget to the question. Burning twenty searches on a lookup wastes turns; doing two searches on a contested synthesis ships a half-checked claim.