AI agents call list_payments to retrieve information from Tabby without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool queries and retrieves payment records without creating, modifying, deleting, or moving money. It is purely a Read operation. While the server handles financial transactions (BNPL payments, refunds), this specific tool only lists/filters existing payments. Low severity because retrieving payment data poses minimal risk; the blast radius is limited to information disclosure.
From the tool's definition Tool name is 'list_payments' and description states 'List payments with filters' — a retrieval operation with no modification or financial movement.
Attacks that exploit this kind of access
List payments with filters. It is categorised as a Read tool in the Tabby MCP Server, which means it retrieves data without modifying state.
Register the Tabby MCP server in PolicyLayer and add a rule for list_payments: 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.
list_payments is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the list_payments 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.
Set action: deny in the PolicyLayer policy for list_payments. 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.
list_payments 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.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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