refund · Tabby MCP: Risk & Policy

WHAT IT DOES

What refund does on Tabby

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

WHY IT NEEDS A POLICY

Why refund needs a policy

Refunding a payment commits a financial obligation by returning money to a customer. This is a core financial operation that affects monetary balances. Severity is high because misuse by an AI agent could refund incorrect amounts, process duplicate refunds, or refund unauthorized transactions, causing direct financial loss.

From the tool's definition Tool name 'refund' and description 'Refund a captured payment' directly indicates movement of money back to a customer, which is a financial obligation and transaction.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

refund Approval-gated

Any call to refund 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": {
    "refund": {
      "deny_if": [
        {
          "conditions": [],
          "on_deny": "Requires human approval."
        }
      ]
    }
  }
}

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PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Tabby, so you can run agents against it safely.

FAQ

Questions about refund

What does the refund tool do? +

Refund a captured payment. It is categorised as a Financial tool in the Tabby MCP Server, which means it involves financial transactions. Block by default and require explicit approval.

How do I enforce a policy on refund? +

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

What risk level is refund? +

refund 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 refund? +

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

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

refund is provided by the Tabby MCP server (theyahia/tabby-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.