xcode_run_tests · Xcode MCP: Risk & Policy

WHAT IT DOES

What xcode_run_tests does on Xcode

AI agents invoke xcode_run_tests to trigger actions in Xcode. 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 xcode_run_tests needs a policy

Running tests via xcodebuild executes arbitrary test code whose behavior depends on the test suite contents and project configuration. While tests are typically intended to be safe, an AI agent could be manipulated to run malicious test code, access sensitive data during test execution, or trigger unintended side effects.

From the tool's definition Tool runs tests using xcodebuild, which executes code. The description explicitly states 'Run tests' and invokes xcodebuild, a command-line tool that compiles and executes test targets. Test execution is inherently an Execute action.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

xcode_run_tests Rate-limited

xcode_run_tests 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": {
    "xcode_run_tests": {
      "limits": [
        {
          "counter": "xcode_run_tests_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 Xcode, so you can run agents against it safely.

FAQ

Questions about xcode_run_tests

What does the xcode_run_tests tool do? +

Run tests using xcodebuild. It is categorised as a Execute tool in the Xcode MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on xcode_run_tests? +

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

What risk level is xcode_run_tests? +

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

Can I rate-limit xcode_run_tests? +

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

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

xcode_run_tests is provided by the Xcode MCP server (raunaksplanet/xcode-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.