Returns the retrieval results only. Good when the client AI needs evidence for its own chain-of-thought or wish to cross-check multiple modes/top-k values cheaply. Retrieves raw context passages from a knowledge base without synthesizing an LLM answer. Client AI must generate the answer and that ...
AI agents call retrieve to retrieve information from Knowledge without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool performs a read-only operation—querying and returning data from a knowledge base without creating, modifying, deleting, executing code, or initiating financial transactions. It retrieves passages for the client AI to process independently, which is characteristic of Read category operations.
From the tool's definition The tool description explicitly states it 'Retrieves raw context passages from a knowledge base' and 'Returns the retrieval results only' without modification or synthesis. The description emphasizes retrieval and evidence gathering with no side effects.
Documented attack patterns abuse exactly the kind of access retrieve gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Knowledge, and nothing reaches the server without passing your rules. This is the rule we recommend for retrieve:
{
"version": "1",
"default": "deny",
"tools": {
"retrieve": {}
}
}retrieve is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Returns the retrieval results only. Good when the client AI needs evidence for its own chain-of-thought or wish to cross-check multiple modes/top-k values cheaply. Retrieves raw context passages from a knowledge base without synthesizing an LLM answer. Client AI must generate the answer and that increases token volume for the client AI. Faster response, good for multiple queries. It is categorised as a Read tool in the Knowledge MCP Server, which means it retrieves data without modifying state.
Register the Knowledge MCP server in PolicyLayer and add a rule for retrieve: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Knowledge. Nothing to install.
retrieve is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the retrieve rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for retrieve. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
retrieve is provided by the Knowledge MCP server (olafgeibig/knowledge-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 6 Knowledge tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
6 Knowledge tools catalogued and risk-classified — across an index of 42,500+ MCP servers.