Find, trace, or investigate code across local or GitHub repos through the dq index - where a symbol is defined, who references it, an existing pattern to reuse, what changed in recent commits, whether a change is risky, or how data flows upstream/downstream. Returns cited findings (file#Lstart-Lend, commit SHA). For third-party library docs use doc-search; to refresh the index run `dq-scan refresh && dq-sql index`.
Answer library/API/config/behavior questions from the dq MCP tools - installed doc sets, offline, cited - instead of memory or the web. Use when you are about to write or explain code that calls a third-party library or tool, or to confirm an API signature, config option, or documented behavior. To search your own source code use code-search; to add a doc set use resolve-doc-source.
Use when adding a documentation source to the dq doc pipeline or asking the best way to ingest a library or site's docs - e.g. 'add docs for X', 'what's the right recipe for <docs-url>', 'resolve doc source'. Resolves the optimal ingest strategy by measurement and adds the recipe to config/doc_sets.toml.