Get historical price bars for a stock.
AI agents call get_stock_bars to retrieve information from Alpaca MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool queries past market data and returns information only. It has no side effects—it does not create, modify, delete, or execute any trades or financial transactions. While the server as a whole includes Financial tools (place_market_order, place_limit_order, close_all_positions, cancel_all_orders), this specific tool is purely informational.
From the tool's definition get_stock_bars retrieves 'historical price bars for a stock' without modifying, deleting, or executing trades. It is a data fetch operation.
Attacks that exploit this kind of access
Get historical price bars for a stock. It is categorised as a Read tool in the Alpaca MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Alpaca MCP Server MCP server in PolicyLayer and add a rule for get_stock_bars: 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 Alpaca MCP Server. Nothing to install.
get_stock_bars 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 get_stock_bars 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 get_stock_bars. 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.
get_stock_bars is provided by the Alpaca MCP Server MCP server (miguelyad26/alpaca-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
Teams ship this data inside their own products. See what a licence covers →