AI agents call get_options_expirations to retrieve information from IsoFinancial-MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves static reference data (options expiration dates) from financial markets. It performs a query with no ability to execute trades, modify accounts, delete data, or commit financial obligations.
From the tool's definition Tool name 'get_options_expirations' and description 'Get options expiration dates' indicate a data retrieval operation with no mutation, side effects, or financial commitment.
Documented attack patterns abuse exactly the kind of access get_options_expirations gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and IsoFinancial-MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for get_options_expirations:
{
"version": "1",
"default": "deny",
"tools": {
"get_options_expirations": {}
}
}get_options_expirations is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Get options expiration dates. It is categorised as a Read tool in the IsoFinancial-MCP MCP Server, which means it retrieves data without modifying state.
Register the IsoFinancial- MCP server in PolicyLayer and add a rule for get_options_expirations: 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 IsoFinancial-MCP. Nothing to install.
get_options_expirations 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_options_expirations 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_options_expirations. 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_options_expirations is provided by the IsoFinancial- MCP server (niels-8/isofinancial-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from IsoFinancial-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.
26 IsoFinancial-MCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.