lexicon_control · Lexicon MCP: Risk & Policy

WHAT IT DOES

What lexicon_control does on Lexicon

AI agents invoke lexicon_control to trigger actions in Lexicon. 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 lexicon_control needs a policy

This tool executes control actions against the Lexicon DJ application rather than simply reading or writing data in a reversible manner. The verb 'Run' and the nature of control actions (e.g., marking items as done, adding shortcuts) suggest triggering application-level operations whose effects depend on which action is invoked.

From the tool's definition Tool description states 'Run a Lexicon control action' with examples like 'Incoming_SelectedDone' and 'Application_Tags_AddShortcut', indicating execution of operations.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

lexicon_control Rate-limited

lexicon_control 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": {
    "lexicon_control": {
      "limits": [
        {
          "counter": "lexicon_control_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 Lexicon, so you can run agents against it safely.

FAQ

Questions about lexicon_control

What does the lexicon_control tool do? +

Run a Lexicon control action (e.g. Incoming_SelectedDone, Application_Tags_AddShortcut). Requires LEXICON_MCP_ALLOW_WRITES=1. It is categorised as a Execute tool in the Lexicon MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on lexicon_control? +

Register the Lexicon MCP server in PolicyLayer and add a rule for lexicon_control: 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 Lexicon. Nothing to install.

What risk level is lexicon_control? +

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

Can I rate-limit lexicon_control? +

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

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

lexicon_control is provided by the Lexicon MCP server (turbotailz/lexicon-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.