lexq_ab_test_start · LexQ MCP: Risk & Policy

WHAT IT DOES

What lexq_ab_test_start does on LexQ

AI agents invoke lexq_ab_test_start to trigger actions in LexQ. 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 lexq_ab_test_start needs a policy

Starting an A/B test triggers an external operation that actively routes live traffic to a challenger policy version, affecting real business rule execution. This is not a simple write/create of data — it initiates a running process with real operational impact.

From the tool's definition 'Start an A/B test on a policy group. Requires a challenger version ID and traffic rate.'

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

lexq_ab_test_start Rate-limited

lexq_ab_test_start 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": {
    "lexq_ab_test_start": {
      "limits": [
        {
          "counter": "lexq_ab_test_start_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 LexQ, so you can run agents against it safely.

FAQ

Questions about lexq_ab_test_start

What does the lexq_ab_test_start tool do? +

Start an A/B test on a policy group. Requires a challenger version ID and traffic rate. It is categorised as a Execute tool in the LexQ MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on lexq_ab_test_start? +

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

What risk level is lexq_ab_test_start? +

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

Can I rate-limit lexq_ab_test_start? +

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

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

lexq_ab_test_start is provided by the LexQ MCP server (lexq-io/lexq-cli). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.