Low Risk

list_services

List available service types for a given origin/destination

How to control list_services ↓

What list_services does on Mcp Ap2

AI agents call list_services to retrieve information from Mcp Ap2 without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

Low Risk

Why list_services needs a policy

This tool retrieves or queries available service type information for routing/origin-destination pairs. It does not create, modify, delete, or execute operations—it only returns information. The context of an Agent-to-Agent Payment Protocol system suggests this lists service options that could be used in payment flows, but the tool itself performs no financial transaction or irreversible action.

From the tool's definition Tool name 'list_services' with description 'List available service types' indicates a data retrieval operation with no side effects. The verb 'list' is a classic read-only query pattern.

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

How to control list_services

PolicyLayer is an MCP gateway — it sits between your AI agents and Mcp Ap2, and nothing reaches the server without passing your rules. This is the rule we recommend for list_services:

policy.json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "list_services": {}
  }
}

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

  1. Create a free account and register Mcp Ap2 — nothing to install.
  2. Add this policy — paste it, or build it visually.
  3. Point your MCP client (Claude, Cursor, anything) at your gateway URL.
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Related tools and policies

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Questions about list_services

What does the list_services tool do? +

List available service types for a given origin/destination. It is categorised as a Read tool in the Mcp Ap2 MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on list_services? +

Register the Mcp Ap2 MCP server in PolicyLayer and add a rule for list_services: 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 Mcp Ap2. Nothing to install.

What risk level is list_services? +

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

Can I rate-limit list_services? +

Yes. Add a rate_limit block to the list_services 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_services completely? +

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

list_services is provided by the Mcp Ap2 MCP server (@codespar/mcp-ap2). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Mcp Ap2 tool call.

Start from Mcp Ap2, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

Free to start. No card required.

1300 Mcp Ap2 tools catalogued and risk-classified — across an index of 43,000+ MCP servers.

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