AI agents use upgrade_to_margin to commit financial operations through Paper MCP Server — usually the final step of a payment, billing, or trading workflow. A call moves real money.
Upgrading to a margin account is a financial commitment that enables leveraged trading with borrowed funds. This changes the account type and financial terms/obligations, representing a significant financial action that could expose the user to margin calls, interest charges, and amplified losses. It falls under Financial as it commits the user to new financial terms and capabilities.
From the tool's definition Upgrade portfolio to margin account
Documented attack patterns abuse exactly the kind of access upgrade_to_margin gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Paper MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for upgrade_to_margin:
{
"version": "1",
"default": "deny",
"tools": {
"upgrade_to_margin": {
"deny_if": [
{
"conditions": [],
"on_deny": "Requires human approval."
}
]
}
}
} Any call to upgrade_to_margin is blocked until a human approves it. The rest of the server keeps working.
Free to start. No card required.
Upgrade portfolio to margin account. It is categorised as a Financial tool in the Paper MCP Server MCP Server, which means it involves financial transactions. Block by default and require explicit approval.
Register the Paper MCP Server MCP server in PolicyLayer and add a rule for upgrade_to_margin: 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 Paper MCP Server. Nothing to install.
upgrade_to_margin is a Financial tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.
Yes. Add a rate_limit block to the upgrade_to_margin 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 upgrade_to_margin. 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.
upgrade_to_margin is provided by the Paper MCP Server MCP server (paperinvest/mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Paper MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
23 Paper MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.