Fetch available option expiration dates for a stock.
AI agents call yfinance_get_option_dates 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 informational data (option expiration dates) about a financial instrument without executing trades, moving money, modifying data, or deleting anything. It is purely a data lookup operation, making it a Read category tool with low severity since misuse poses no direct harm.
From the tool's definition Tool name contains 'get_' and description states 'Fetch available option expiration dates' — a retrieval operation with no modification, deletion, or financial transaction capability. It queries metadata about options availability.
Attacks that exploit this kind of access
Fetch available option expiration dates for a stock. 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 yfinance_get_option_dates: 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.
yfinance_get_option_dates 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 yfinance_get_option_dates 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 yfinance_get_option_dates. 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.
yfinance_get_option_dates is provided by the Yahoo Finance MCP Server MCP server (narumiruna/yfinance-mcp). 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.
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