Get market movers for the S&P 500 index ($SPX).
AI agents call schwab_get_movers_sp500 to retrieve information from Open Stocks MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves and queries publicly available market data about S&P 500 index movements. It performs no modifications, deletions, executions, or financial transactions. It is purely informational and read-only, making it the lowest risk category.
From the tool's definition Tool name 'schwab_get_movers_sp500' and description 'Get market movers for the S&P 500 index' indicate retrieval of market data. The verb 'Get' and the read-only nature of querying market indices confirm no side effects or state changes.
Documented attack patterns abuse exactly the kind of access schwab_get_movers_sp500 gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Open Stocks MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for schwab_get_movers_sp500:
{
"version": "1",
"default": "deny",
"tools": {
"schwab_get_movers_sp500": {}
}
}schwab_get_movers_sp500 is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
Free to start. No card required.
Get market movers for the S&P 500 index ($SPX). 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 schwab_get_movers_sp500: 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.
schwab_get_movers_sp500 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 schwab_get_movers_sp500 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 schwab_get_movers_sp500. 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.
schwab_get_movers_sp500 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.