# MCP The daemon exposes the knowledge base over MCP as a search tool (`ask_knowledge`) and as per-file resources. ## Tool: `ask_knowledge` Agents call `ask_knowledge` mid-task to retrieve context on demand: ```json { "tool": "ask_knowledge", "query": "PR review standards" } ``` The tool returns `` sections, ordered by relevance score. The tool only registers when the selected retrieval engine is ready — if it is missing from the tool list, check `bento daemon logs` for `knowledge: index ready`. | Parameter | Default | Meaning | |---|---|---| | `query` | — | What to search for. | | `limit` | [`knowledge.retrieval.topK`](/knowledge-base/config) | Max results per source, 1 to 20. | | `rerank` | [`knowledge.retrieval.rerank`](/knowledge-base/config) | Enable the optional reranking stage of the retrieval engine. | | `method` | [`knowledge.retrieval.method`](/knowledge-base/config), else `hybrid` | Retrieval [method](/knowledge-base/modes): `bm25`, `vector`, or `hybrid`. | Set `knowledge.retrieval.method` to move agent search off `hybrid` for the whole daemon. A `hybrid` search pays for a lexical pass and for a semantic pass, which is slow on a host with no GPU. A `bm25` search and a `vector` search each run one pass. This key is not `defaults.knowledge.method`, which selects daemon-side retrieval for a run, and which the daemon rejects next to `delivery: search`. A per-pipeline `knowledge:` block does not reach the tool. ## Resources The daemon registers each markdown file in `wiki/`, `blueprints/`, and `recipes/` as an MCP resource at startup: ``` wiki://git-workflow blueprint://feature-evaluation-rubric recipe://add-agent ``` Any MCP client browses and reads these resources directly, without a call to `ask_knowledge`. ## Automatic injection During the `retrieve` phase of a pipeline run with a retrieving [method](/knowledge-base/modes) (`bm25`/`vector`/`hybrid`), the daemon queries the index and injects matching chunks into the agent prompt. Tune retrieval depth via [`knowledge.retrieval.topK`](/knowledge-base/config).