recall · Nexus Memory MCP: Risk & Policy

WHAT IT DOES

What recall does on Nexus Memory

AI agents call recall to retrieve information from Nexus Memory without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

WHY IT NEEDS A POLICY

Why recall needs a policy

This tool searches and retrieves stored memory data without modifying, deleting, or executing operations. It is purely informational, returning context from prior sessions. The low severity reflects minimal blast radius—misuse would at worst return irrelevant or stale context, but cannot alter state or trigger external actions.

From the tool's definition Tool name 'recall' and description 'Search memories. Returns relevant context from past sessions.' indicate a query/retrieval operation with no side effects.

Attacks that exploit this kind of access

Questions about recall

What does the recall tool do? +

Search memories. Returns relevant context from past sessions. It is categorised as a Read tool in the Nexus Memory MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on recall? +

Register the Nexus Memory 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 Nexus Memory. Nothing to install.

What risk level is recall? +

recall is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit recall? +

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.

How do I block recall completely? +

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.

What MCP server provides recall? +

recall is provided by the Nexus Memory MCP server (neboy72/nexus-memory). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.