login · Mail Tm MCP Server MCP: Risk & Policy

Q: What risk level is login?

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

WHAT IT DOES

What login does on Mail Tm MCP Server

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

WHY IT NEEDS A POLICY

Why login needs a policy

Login is a state-changing operation that creates or updates authentication state, placing it in Write rather than Read. It's not Destructive (reversible), Execute (no external command execution), or Financial.

From the tool's definition Tool performs authentication/session management ('Log in to an existing mail.tm account'), which modifies application state by establishing a user session and credentials.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

login 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": {
    "login": {
      "limits": [
        {
          "counter": "login_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 Mail Tm MCP Server, so you can run agents against it safely.

FAQ

Questions about login

What does the login tool do? +

Log in to an existing mail.tm account. It is categorised as a Write tool in the Mail Tm MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on login? +

Register the Mail Tm MCP Server MCP server in PolicyLayer and add a rule for login: 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 Mail Tm MCP Server. Nothing to install.

What risk level is login? +

Can I rate-limit login? +

Yes. Add a rate_limit block to the login 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 login completely? +

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

login is provided by the Mail Tm MCP Server MCP server (opastorello/mailtm-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.