Medium Risk

ebay_create_listing

Create a new fixed-price listing.\n\nUses the Trading API (AddFixedPriceItem). Requires complete item details.\n\nRequired: User OAuth token.

How to control ebay_create_listing ↓

AI agents use ebay_create_listing to create or update resources in Ebay — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Ebay environment.

Medium Risk

This tool creates new data (a listing) in the eBay system. It is reversible—listings can be delisted or ended—so it does not rise to Destructive. While the tool operates within the eBay marketplace ecosystem and affects commerce, it does not directly transfer money or create financial obligations, so it is not Financial. The tool's primary action is data creation, placing it squarely in the Write category.

From the tool's definition Creates a new fixed-price listing via Trading API (AddFixedPriceItem); modifies eBay inventory and catalog by adding a new listing entry.

Documented attack patterns abuse exactly the kind of access ebay_create_listing gives an agent:

PolicyLayer is an MCP gateway — it sits between your AI agents and Ebay, and nothing reaches the server without passing your rules. This is the rule we recommend for ebay_create_listing:

policy.json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "ebay_create_listing": {
      "limits": [
        {
          "counter": "ebay_create_listing_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

ebay_create_listing stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

  1. Create a free account and register Ebay — nothing to install.
  2. Add this policy — paste it, or build it visually.
  3. Point your MCP client (Claude, Cursor, anything) at your gateway URL.
LIMIT THIS TOOL →

Free to start. No card required.

Go deeper

What does the ebay_create_listing tool do? +

Create a new fixed-price listing.\n\nUses the Trading API (AddFixedPriceItem). Requires complete item details.\n\nRequired: User OAuth token. It is categorised as a Write tool in the Ebay MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on ebay_create_listing? +

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

ebay_create_listing is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit ebay_create_listing? +

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

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

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

Enforce policy on every Ebay tool call.

Deterministic rules across all 332 Ebay tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.

Free to start. No card required.

332 Ebay tools catalogued and risk-classified — across an index of 42,500+ MCP servers.

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