buy_now

A financial tool on the Ebay MCP server.

SERVEREbay SOURCEacato/ebay-mcp

Critical RISK CLASS

Category Financial

Parameters 00 required

Recommended Approval-gatedsee the rule below

Registry record Grade D, identity unverified Pull the record →

This record as markdown: /tools/acato-ebay-mcp/buy-now.md

WHAT IT DOES

What buy_now does on Ebay

AI agents use buy_now to commit financial operations through Ebay, usually the final step of a payment, billing, or trading workflow. A call moves real money.

RISK

Why buy_now is rated Critical

'Buy Now' on eBay is a direct purchase action that immediately commits financial obligations — it charges the buyer's payment method for the item price. Even with an empty description, the tool name combined with the server's explicit 'buy' workflow context and financial sibling tools (place_bid, make_best_offer) makes this clearly a Financial category tool. Misuse could result in unauthorized purchases.

From the tool's definition Tool name 'buy_now' on a server described as enabling 'buy' workflows via eBay APIs; sibling tools include 'place_bid' and 'make_best_offer', confirming financial transaction context.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs buy_now safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Ebay, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For buy_now, this is the rule to start with:

buy_now Approval-gated

Any call to buy_now is blocked until a human approves it. The rest of the server keeps working.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "buy_now": {
      "deny_if": [
        {
          "conditions": [],
          "on_deny": "Requires human approval."
        }
      ]
    }
  }
}

GATE THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Ebay, apply this rule, and every buy_now call is checked against it from then on.

FAQ

Questions about buy_now

What does the buy_now tool do? +

buy_now is a financial tool on the Ebay MCP server. It is categorised as a Financial tool in the Ebay MCP Server, which means it involves financial transactions. Block by default and require explicit approval.

How do I enforce a policy on buy_now? +

Register the Ebay MCP server in PolicyLayer and add a rule for buy_now: 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 Ebay. Nothing to install.

What risk level is buy_now? +

buy_now is a Financial tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.

Can I rate-limit buy_now? +

Yes. Add a rate_limit block to the buy_now 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 buy_now completely? +

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

buy_now is provided by the Ebay MCP server (acato/ebay-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

More on Ebay, and thousands of servers like it.

This server

All 15 Ebay tools → Critical-risk tools on this server →

Across the catalogue

All critical-risk MCP tools → The MCP Attack Database →

Guides

Govern MCP payment tools →Human-in-the-loop →Tool call approval →