AI agents use request_booking_link to commit financial operations through Flights MCP — usually the final step of a payment, billing, or trading workflow. A call moves real money.
While this tool appears to generate a booking link rather than directly charge a user, it initiates the purchase/booking flow for a flight, which is a financial commitment. The tool sits at the boundary of Financial and Write, but since it directly facilitates a financial transaction (flight purchase), Financial is the most appropriate and most severe applicable category.
From the tool's definition 'Request link for booking a flight option' — initiates the booking process for a flight, which leads to a financial transaction (purchasing a flight ticket).
Documented attack patterns abuse exactly the kind of access request_booking_link gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Flights MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for request_booking_link:
{
"version": "1",
"default": "deny",
"tools": {
"request_booking_link": {
"deny_if": [
{
"conditions": [],
"on_deny": "Requires human approval."
}
]
}
}
}Any call to request_booking_link is blocked until a human approves it. The rest of the server keeps working.
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Request link for booking a flight option. It is categorised as a Financial tool in the Flights MCP MCP Server, which means it involves financial transactions. Block by default and require explicit approval.
Register the Flights MCP server in PolicyLayer and add a rule for request_booking_link: 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 Flights MCP. Nothing to install.
request_booking_link is a Financial tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.
Yes. Add a rate_limit block to the request_booking_link 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 request_booking_link. 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.
request_booking_link is provided by the Flights MCP server (maratsarbasov/flights-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Flights MCP, 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 Flights MCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.