list_active_tests

THE RISK

Low Risk

Why list_active_tests needs a policy

This tool retrieves information about active test processes without modifying, executing, or deleting anything. It is a straightforward informational read operation with minimal blast radius if misused by an AI agent.

From the tool's definition Tool name is 'list_active_tests' and description states 'List all currently connected test processes' — this is a query/list operation with no side effects.

Documented attack patterns abuse exactly the kind of access list_active_tests gives an agent:

POLICY

How to control list_active_tests

PolicyLayer is an MCP gateway — it sits between your AI agents and Testing, and nothing reaches the server without passing your rules. This is the rule we recommend for list_active_tests:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "list_active_tests": {}
  }
}

list_active_tests is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.

Create a free account and register Testing — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

CAP THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Testing tools

Destructive finalize_test Finalize the test by removing connect() call and optionally cleaning up markers Execute execute_test_step Execute code directly in the connected test client and get back the updated DOM state and Read get_current_test_state Get the current state of a connected test, including DOM, snapshot, console logs, and avai Read get_generated_code Get all generated code blocks from a test file

All 5 Testing tools →

Read tools on other servers

M-Team MCP Server get_torrent_detail YouTube MCP Server search_channel Android Forensics ADB MCP Server parse_browser_history 0xarchive web3_challenge

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Data exfiltration → How read access becomes an exfiltration channel when chained with untrusted content.
MCP token cost → What connecting this server costs in context-window tokens on every request.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about list_active_tests

What does the list_active_tests tool do? +

List all currently connected test processes. It is categorised as a Read tool in the Testing MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on list_active_tests? +

Register the Testing MCP server in PolicyLayer and add a rule for list_active_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 Testing. Nothing to install.

What risk level is list_active_tests? +

list_active_tests is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit list_active_tests? +

Yes. Add a rate_limit block to the list_active_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 list_active_tests completely? +

Set action: deny in the PolicyLayer policy for list_active_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 list_active_tests? +

list_active_tests is provided by the Testing MCP server (mcpland/testing-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Testing tool call.

Start from Testing, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →