pcal_translate · Tlaplus MCP: Risk & Policy

WHAT IT DOES

What pcal_translate does on Tlaplus

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

WHY IT NEEDS A POLICY

Why pcal_translate needs a policy

The tool writes to an existing file on disk (in-place modification), which is a reversible write operation — the file is updated but not permanently destroyed, and the original content between translation markers is replaced/updated. This fits the Write category. Severity is medium because it modifies source files automatically, which could overwrite hand-edited translation sections if misused.

From the tool's definition Modifies the .tla file in-place by inserting/updating the TLA+ translation between the \* BEGIN TRANSLATION and \* END TRANSLATION markers

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

pcal_translate Rate-limited

pcal_translate 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": {
    "pcal_translate": {
      "limits": [
        {
          "counter": "pcal_translate_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 Tlaplus, so you can run agents against it safely.

FAQ

Questions about pcal_translate

What does the pcal_translate tool do? +

Translate PlusCal algorithm embedded in a TLA+ file to TLA+. Modifies the .tla file in-place by inserting/updating the TLA+ translation between the \\* BEGIN TRANSLATION and \\* END TRANSLATION markers. It is categorised as a Write tool in the Tlaplus MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on pcal_translate? +

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

What risk level is pcal_translate? +

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

Can I rate-limit pcal_translate? +

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

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

pcal_translate is provided by the Tlaplus MCP server (richashworth/tlaplus-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.