AI agents call top_movers 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 and queries stock market data about top-performing securities without creating, modifying, deleting, or executing any trades or commands. It is purely informational. The low severity reflects minimal blast radius—misuse returns market data only, with no financial, destructive, or operational consequences.
From the tool's definition Tool name 'top_movers' and description 'Gets top 20 movers on Robinhood' indicate a data retrieval operation. The verb 'Gets' combined with 'top 20 movers' (market data) shows no modification, deletion, or execution of operations.
Documented attack patterns abuse exactly the kind of access top_movers 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 top_movers:
{
"version": "1",
"default": "deny",
"tools": {
"top_movers": {}
}
}top_movers 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 top 20 movers on Robinhood. 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 top_movers: 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.
top_movers 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 top_movers 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 top_movers. 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.
top_movers 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.