# list_cities

List all covered cities (slug, federal state, population, coverage). Takes no arguments. Call this first to discover valid city slugs before invoking any city-scoped tool. Read-only.

Agent View of the PolicyLayer registry record for `list_cities`. HTML page: https://policylayer.com/tools/dev-infranode-infranode/list-cities

## Facts

- Tool: `list_cities`
- Server: InfraNode (`https://mcp.infranode.dev/mcp`) — https://policylayer.com/tools/dev-infranode-infranode.md
- Homepage: https://github.com/street1983nk/infranode
- Risk category: Read (Low risk)
- Registry record: grade C, identity unverified
- Server auth posture: open
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Allowed

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "list_cities",
    "arguments": {}
  }
}
```

## Why list_cities is rated Low

This tool retrieves and queries data without modification, deletion, or execution of external operations. It is a pure read operation used for data discovery, fitting clearly into the Read category with minimal security risk.

From the tool's own definition: "Tool description explicitly states 'Read-only' and performs listing operation ('List all covered cities') with no arguments and no side effects. Returns metadata (slug, federal state, population, coverage) for discovery purposes."

## Use case

AI agents call list_cities to retrieve information from InfraNode without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

## Recommended policy (PolicyLayer)

Verdict: **Allowed**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches InfraNode:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "list_cities": {}
  }
}
```

## Other tools on InfraNode (11)

- `air_quality` — Read — https://policylayer.com/tools/dev-infranode-infranode/air-quality.md
- `compare` — Read — https://policylayer.com/tools/dev-infranode-infranode/compare.md
- `get_city` — Read — https://policylayer.com/tools/dev-infranode-infranode/get-city.md
- `get_city_overview` — Read — https://policylayer.com/tools/dev-infranode-infranode/get-city-overview.md
- `get_city_resource` — Read — https://policylayer.com/tools/dev-infranode-infranode/get-city-resource.md
- `pois` — Read — https://policylayer.com/tools/dev-infranode-infranode/pois.md
- `sources` — Read — https://policylayer.com/tools/dev-infranode-infranode/sources.md
- `station_board_arrivals` — Read — https://policylayer.com/tools/dev-infranode-infranode/station-board-arrivals.md
- `station_board_departures` — Read — https://policylayer.com/tools/dev-infranode-infranode/station-board-departures.md
- `transit_departures` — Read — https://policylayer.com/tools/dev-infranode-infranode/transit-departures.md
- `weather` — Read — https://policylayer.com/tools/dev-infranode-infranode/weather.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=dev-infranode-infranode · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/dev-infranode-infranode