tdd_mutation_score · Promethean OS MCP: Risk & Policy

WHAT IT DOES

What tdd_mutation_score does on Promethean OS MCP

AI agents invoke tdd_mutation_score to trigger actions in Promethean OS MCP. 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 tdd_mutation_score needs a policy

This tool invokes Stryker, an external mutation testing framework that modifies code, runs tests, and generates metrics. While the end result is a report (Read-like output), the action itself is Execute: it triggers subprocess execution with side effects (CPU usage, test execution, file system operations).

From the tool's definition "Run Stryker mutation testing" - executes mutation testing framework with externally observable effects (test suite execution, code modification).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

tdd_mutation_score Rate-limited

tdd_mutation_score 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": {
    "tdd_mutation_score": {
      "limits": [
        {
          "counter": "tdd_mutation_score_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 Promethean OS MCP, so you can run agents against it safely.

FAQ

Questions about tdd_mutation_score

What does the tdd_mutation_score tool do? +

Run Stryker mutation testing and return the score (fail if below minScore). It is categorised as a Execute tool in the Promethean OS MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on tdd_mutation_score? +

Register the Promethean OS MCP server in PolicyLayer and add a rule for tdd_mutation_score: 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 Promethean OS MCP. Nothing to install.

What risk level is tdd_mutation_score? +

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

Can I rate-limit tdd_mutation_score? +

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

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

tdd_mutation_score is provided by the Promethean OS MCP server (octave-commons/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.