make_best_offer

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/make-best-offer.md

WHAT IT DOES

What make_best_offer does on Ebay

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

RISK

Why make_best_offer is rated Critical

On eBay, 'Make Best Offer' is a financial transaction feature where a buyer submits a monetary offer on a listing, which if accepted creates a binding purchase obligation. Given the server context (buyer-side workflows with bid/buy capabilities), this tool almost certainly submits a financial offer.

From the tool's definition Tool name 'make_best_offer' on an eBay server with sibling tools including 'place_bid', 'buy_now' — all financial transaction tools. 'Best Offer' on eBay is a formal price negotiation that can result in a binding purchase commitment.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs make_best_offer 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 make_best_offer, this is the rule to start with:

make_best_offer Approval-gated

Any call to make_best_offer 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": {
    "make_best_offer": {
      "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 make_best_offer call is checked against it from then on.

FAQ

Questions about make_best_offer

What does the make_best_offer tool do? +

make_best_offer 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 make_best_offer? +

Register the Ebay MCP server in PolicyLayer and add a rule for make_best_offer: 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 make_best_offer? +

make_best_offer 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 make_best_offer? +

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

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

make_best_offer 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 →