tdd_coverage · Promethean OS MCP: Risk & Policy

WHAT IT DOES

What tdd_coverage does on Promethean OS MCP

AI agents invoke tdd_coverage 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_coverage needs a policy

This tool triggers execution of test runners and coverage tools (c8 and AVA), making it an Execute category tool. While test execution is generally lower risk than arbitrary shell commands, it still runs external code whose behavior depends on the codebase and test configuration.

From the tool's definition Tool description explicitly states "Run c8+AVA" - c8 is a code coverage tool and AVA is a test runner. The verb "Run" indicates execution of external processes and scripts.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

tdd_coverage Rate-limited

tdd_coverage 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_coverage": {
      "limits": [
        {
          "counter": "tdd_coverage_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_coverage

What does the tdd_coverage tool do? +

Run c8+AVA to produce coverage summary; enforce optional thresholds. 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_coverage? +

Register the Promethean OS MCP server in PolicyLayer and add a rule for tdd_coverage: 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_coverage? +

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

Can I rate-limit tdd_coverage? +

Yes. Add a rate_limit block to the tdd_coverage 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_coverage completely? +

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

tdd_coverage 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.