keyid_set_signature · KeyID Agent Kit MCP: Risk & Policy

WHAT IT DOES

What keyid_set_signature does on KeyID Agent Kit

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

WHY IT NEEDS A POLICY

Why keyid_set_signature needs a policy

This tool creates or modifies email signature data reversibly—a signature can be changed, removed, or updated at any time without permanent loss. It does not execute code, delete data, or move money.

From the tool's definition Tool modifies email signature settings ('Set the email signature'), which creates or updates configuration data associated with the agent's email account.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

keyid_set_signature Rate-limited

keyid_set_signature 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": {
    "keyid_set_signature": {
      "limits": [
        {
          "counter": "keyid_set_signature_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 KeyID Agent Kit, so you can run agents against it safely.

FAQ

Questions about keyid_set_signature

What does the keyid_set_signature tool do? +

Set the email signature for this agent. It is categorised as a Write tool in the KeyID Agent Kit MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on keyid_set_signature? +

Register the KeyID Agent Kit MCP server in PolicyLayer and add a rule for keyid_set_signature: 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 KeyID Agent Kit. Nothing to install.

What risk level is keyid_set_signature? +

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

Can I rate-limit keyid_set_signature? +

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

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

keyid_set_signature is provided by the KeyID Agent Kit MCP server (keyid-ai/agent-kit). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.