AI agents call list_categories to retrieve information from Memoraeu without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves metadata about existing categories in the memory system. It performs no writes, deletes, executions, or financial operations. The action is a simple data retrieval operation with no blast radius if misused by an AI agent—it can only expose what categories exist and their usage frequency, which is informational only.
From the tool's definition Tool name 'list_categories' and description 'Return existing categories sorted by usage' indicate a read-only query operation that retrieves and lists data without modification or side effects.
Attacks that exploit this kind of access
Return existing categories sorted by usage. It is categorised as a Read tool in the Memoraeu MCP Server, which means it retrieves data without modifying state.
Register the Memoraeu MCP server in PolicyLayer and add a rule for list_categories: 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 Memoraeu. Nothing to install.
list_categories 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 list_categories 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 list_categories. 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.
list_categories is provided by the Memoraeu MCP server (pquattro/memoraeu-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
Teams ship this data inside their own products. See what a licence covers →