identity_sign · Mailgent MCP Server MCP: Risk & Policy

WHAT IT DOES

What identity_sign does on Mailgent MCP Server

AI agents invoke identity_sign to trigger actions in Mailgent MCP Server. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why identity_sign needs a policy

Signing arbitrary data with a cryptographic identity is an Execute-class operation: it triggers an external cryptographic operation whose effects depend on the data provided. Misuse could allow an AI agent to sign malicious payloads, authorize actions, or impersonate the identity in external systems, making the blast radius high.

From the tool's definition 'Sign arbitrary data with this identity'

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

identity_sign Rate-limited

identity_sign stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "identity_sign": {
      "limits": [
        {
          "counter": "identity_sign_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about identity_sign

What does the identity_sign tool do? +

Sign arbitrary data with this identity. It is categorised as a Execute tool in the Mailgent MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on identity_sign? +

Register the Mailgent MCP Server MCP server in PolicyLayer and add a rule for identity_sign: 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 Mailgent MCP Server. Nothing to install.

What risk level is identity_sign? +

identity_sign is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit identity_sign? +

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

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

identity_sign is provided by the Mailgent MCP Server MCP server (loomal-ai/loomal-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.