Search memory for past observations using natural language. Returns results ranked by semantic similarity.
AI agents call recall to retrieve information from GraphHub without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool searches and retrieves stored observations from memory using semantic matching. It performs a query operation that returns ranked results without side effects, data modification, or code execution. The retrieval of past observations for context is a foundational Read category operation.
From the tool's definition Tool name 'recall' and description 'Search memory for past observations using natural language. Returns results ranked by semantic similarity' indicate a retrieval-only operation with no modification, deletion, or execution of external actions.
Documented attack patterns abuse exactly the kind of access recall gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and GraphHub, and nothing reaches the server without passing your rules. This is the rule we recommend for recall:
{
"version": "1",
"default": "deny",
"tools": {
"recall": {}
}
}recall is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Search memory for past observations using natural language. Returns results ranked by semantic similarity. It is categorised as a Read tool in the GraphHub MCP Server, which means it retrieves data without modifying state.
Register the GraphHub MCP server in PolicyLayer and add a rule for recall: 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 GraphHub. Nothing to install.
recall 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 recall 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 recall. 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.
recall is provided by the GraphHub MCP server (slnquangtran/graph-hub). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from GraphHub, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
32 GraphHub tools catalogued and risk-classified — across an index of 43,000+ MCP servers.