start_user_auth

A execute tool on the Ebay MCP server.

SERVEREbay SOURCEacato/ebay-mcp

High RISK CLASS

Category Execute

Parameters 00 required

Recommended Rate-limitedsee the rule below

Registry record Grade D, identity unverified Pull the record →

This record as markdown: /tools/acato-ebay-mcp/start-user-auth.md

WHAT IT DOES

What start_user_auth does on Ebay

AI agents invoke start_user_auth to trigger actions in Ebay. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call: builds kicked off, notifications sent, workflows started.

RISK

Why start_user_auth is rated High

Authentication initiation is an execute-category action that triggers an external operation (auth flow) whose downstream effects depend on user interaction and subsequent tool calls. While not directly destructive or financial itself, it enables access to financial tools (buy_now, make_best_offer) and account management.

From the tool's definition Tool name 'start_user_auth' indicates initiation of authentication flow; sibling tools include financial operations like 'buy_now' and 'make_best_offer' that require authenticated access. Description is empty, limiting direct evidence.

Attacks that exploit this kind of access

RECOMMENDED RULE

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

start_user_auth Rate-limited

start_user_auth stays usable, but rate-capped: a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "start_user_auth": {
      "limits": [
        {
          "counter": "start_user_auth_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL → Instant setup, no code required.

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

FAQ

Questions about start_user_auth

What does the start_user_auth tool do? +

start_user_auth is a execute tool on the Ebay MCP server. It is categorised as a Execute tool in the Ebay MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on start_user_auth? +

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

start_user_auth is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit start_user_auth? +

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

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

start_user_auth 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 → High-risk tools on this server →

Across the catalogue

start_devtools_monitoring on Percepta MCP Server →team_manager_start_room on Team Manager MCP →start_etw_trace on Procmon → All high-risk MCP tools → The MCP Attack Database →

Guides

Govern code and CI agents →Agent sandbox →Least privilege for MCP →