AI agents call list_invoices to retrieve information from PayPal 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 invoice data without creating, modifying, deleting, or executing any operations. It is a straightforward read operation. Severity is low because listing invoices exposes financial information but does not move money or commit financial obligations.
From the tool's definition Tool name is 'list_invoices' and description states 'List invoices with optional pagination and filtering' — purely a retrieval operation with no side effects.
Documented attack patterns abuse exactly the kind of access list_invoices gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and PayPal, and nothing reaches the server without passing your rules. This is the rule we recommend for list_invoices:
{
"version": "1",
"default": "deny",
"tools": {
"list_invoices": {}
}
}list_invoices is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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List invoices with optional pagination and filtering. It is categorised as a Read tool in the PayPal MCP Server, which means it retrieves data without modifying state.
Register the PayPal MCP server in PolicyLayer and add a rule for list_invoices: 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 PayPal. Nothing to install.
list_invoices 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_invoices 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_invoices. 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_invoices is provided by the PayPal MCP server (paypal/agent-toolkit). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 30 PayPal tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
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30 PayPal tools catalogued and risk-classified — across an index of 42,500+ MCP servers.