Get historical stock prices (OHLCV) for a ticker
AI agents call get_historical_stock_prices to retrieve information from Yahoo Finance MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves historical stock price data without creating, modifying, deleting, or executing any operations. It is a straightforward query operation that returns publicly available financial information. The blast radius of misuse is minimal—an agent could only over-query or access data for unwanted tickers, but cannot modify data or commit financial transactions.
From the tool's definition Tool name 'get_historical_stock_prices' and description 'Get historical stock prices (OHLCV) for a ticker' indicate data retrieval with no side effects. OHLCV (Open, High, Low, Close, Volume) is read-only market data.
Attacks that exploit this kind of access
Get historical stock prices (OHLCV) for a ticker. It is categorised as a Read tool in the Yahoo Finance MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Yahoo Finance MCP Server MCP server in PolicyLayer and add a rule for get_historical_stock_prices: 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 Yahoo Finance MCP Server. Nothing to install.
get_historical_stock_prices 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_historical_stock_prices 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_historical_stock_prices. 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_historical_stock_prices is provided by the Yahoo Finance MCP Server MCP server (refself/yahoo-finance-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 →