tlc_check · Tlaplus MCP: Risk & Policy

WHAT IT DOES

What tlc_check does on Tlaplus

AI agents invoke tlc_check to trigger actions in Tlaplus. 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 tlc_check needs a policy

This tool executes the TLC model checker, an external process that performs exhaustive state-space exploration of a TLA+ specification. It runs code/toolchain commands on the host system. While it reads a spec file, its primary action is executing an external program (TLC) whose resource consumption (CPU, memory, time) can be significant and whose effects depend on the specification provided.

From the tool's definition "Run TLC model checker in exhaustive breadth-first mode" and "Checks all reachable states against invariants, properties"

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

tlc_check Rate-limited

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

FAQ

Questions about tlc_check

What does the tlc_check tool do? +

Run TLC model checker in exhaustive breadth-first mode to verify a TLA+ specification. Checks all reachable states against invariants, properties, and (optionally) deadlock freedom. It is categorised as a Execute tool in the Tlaplus MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on tlc_check? +

Register the Tlaplus MCP server in PolicyLayer and add a rule for tlc_check: 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 tlc_check? +

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

Can I rate-limit tlc_check? +

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

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

tlc_check 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.