Get live departure information for a station
AI agents call get_live_departures to retrieve information from Mcp National Rail without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves and queries live train departure data from National Rail's Realtime Trains API. It performs a read-only operation with no ability to modify, delete, or execute actions. There is no financial impact, no code execution, and no irreversible changes. The tool simply returns information to the caller.
From the tool's definition Tool name 'get_live_departures' and description 'Get live departure information for a station' indicate data retrieval with no modification or side effects.
Documented attack patterns abuse exactly the kind of access get_live_departures gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Mcp National Rail, and nothing reaches the server without passing your rules. This is the rule we recommend for get_live_departures:
{
"version": "1",
"default": "deny",
"tools": {
"get_live_departures": {}
}
}get_live_departures is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Get live departure information for a station. It is categorised as a Read tool in the Mcp National Rail MCP Server, which means it retrieves data without modifying state.
Register the Mcp National Rail MCP server in PolicyLayer and add a rule for get_live_departures: 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 National Rail. Nothing to install.
get_live_departures is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the get_live_departures 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.
Set action: deny in the PolicyLayer policy for get_live_departures. 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.
get_live_departures is provided by the Mcp National Rail MCP server (lucygoodchild/mcp-national-rail). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Mcp National Rail, 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.
4 Mcp National Rail tools catalogued and risk-classified — across an index of 43,000+ MCP servers.