AI agents call subscription_fees to retrieve information from Open Stocks MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves subscription fee data from Robinhood—a read-only query with no side effects. While it relates to financial information, it does not move money, commit financial obligations, or execute trading actions. The 'gets' verb confirms data retrieval rather than modification or execution. Exposure risk is low because misuse would only expose fee information, not enable unauthorized transactions.
From the tool's definition Tool name 'subscription_fees' and description 'Gets Robinhood Gold subscription fees' indicate a query operation that retrieves financial information without modifying or executing any transactions.
Documented attack patterns abuse exactly the kind of access subscription_fees gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Open Stocks MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for subscription_fees:
{
"version": "1",
"default": "deny",
"tools": {
"subscription_fees": {}
}
}subscription_fees is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
Free to start. No card required.
Gets Robinhood Gold subscription fees. It is categorised as a Read tool in the Open Stocks MCP MCP Server, which means it retrieves data without modifying state.
Register the Open Stocks MCP server in PolicyLayer and add a rule for subscription_fees: 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 Open Stocks MCP. Nothing to install.
subscription_fees 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 subscription_fees 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 subscription_fees. 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.
subscription_fees is provided by the Open Stocks MCP server (open-agent-tools/open-stocks-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Open Stocks MCP, 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.
152 Open Stocks MCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.