acknowledge_message · MCP Agent Mail MCP: Risk & Policy

WHAT IT DOES

What acknowledge_message does on MCP Agent Mail

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

WHY IT NEEDS A POLICY

Why acknowledge_message needs a policy

The name 'acknowledge_message' suggests marking a message as acknowledged/read, which is a state-modification operation (Write). In messaging systems, acknowledgment typically updates message state irreversibly but is not truly destructive. Confidence is low due to empty description; the server context (message threading, inbox) supports a Write classification.

From the tool's definition Tool name: acknowledge_message; description is empty and uninformative.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

acknowledge_message Rate-limited

acknowledge_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": {
    "acknowledge_message": {
      "limits": [
        {
          "counter": "acknowledge_message_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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Instant setup, no code required.

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

FAQ

Questions about acknowledge_message

What does the acknowledge_message tool do? +

acknowledge_message. It is categorised as a Write tool in the MCP Agent Mail MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on acknowledge_message? +

Register the MCP Agent Mail MCP server in PolicyLayer and add a rule for acknowledge_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 MCP Agent Mail. Nothing to install.

What risk level is acknowledge_message? +

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

Can I rate-limit acknowledge_message? +

Yes. Add a rate_limit block to the acknowledge_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 acknowledge_message completely? +

Set action: deny in the PolicyLayer policy for acknowledge_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 acknowledge_message? +

acknowledge_message is provided by the MCP Agent Mail MCP server (omelchmichael/mcp_agent_mail). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.