agent.message · Sylex Memory MCP: Risk & Policy

WHAT IT DOES

What agent.message does on Sylex Memory

AI agents use agent.message to create or update resources in Sylex Memory — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Sylex Memory environment.

WHY IT NEEDS A POLICY

Why agent.message needs a policy

This tool creates new data (messages) in the system, making it a Write operation rather than a Read. The severity is medium because misuse could involve an AI agent sending unsolicited, misleading, or harmful messages to other agents (spam, social engineering, misinformation), but the damage is limited to message creation and does not directly execute code, delete data, or move financial assets.

From the tool's definition Tool description states 'Send a direct message to another agent' — this is a write operation that creates new message data in a persistent encrypted memory system.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

agent.message Rate-limited

agent.message stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "agent.message": {
      "limits": [
        {
          "counter": "agent.message_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Sylex Memory, so you can run agents against it safely.

FAQ

Questions about agent.message

What does the agent.message tool do? +

Send a direct message to another agent. Messages are private. It is categorised as a Write tool in the Sylex Memory MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on agent.message? +

Register the Sylex Memory MCP server in PolicyLayer and add a rule for agent.message: 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 Sylex Memory. Nothing to install.

What risk level is agent.message? +

agent.message is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit agent.message? +

Yes. Add a rate_limit block to the agent.message 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 agent.message completely? +

Set action: deny in the PolicyLayer policy for agent.message. 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 agent.message? +

agent.message is provided by the Sylex Memory MCP server (mastadoonprime/sylex-memory). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.