List all supported ETF tickers.
AI agents call list_etf_tickers to retrieve information from Marketstack MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool performs a simple data retrieval operation that queries a static list of supported ETF ticker symbols from the Marketstack API. It has no capability to modify data, execute code, delete information, or affect financial transactions. The blast radius of misuse is minimal—an AI agent listing ETF tickers cannot cause harm. Classification as Read is appropriate.
From the tool's definition Tool name 'list_etf_tickers' and description 'List all supported ETF tickers' indicate a retrieval operation with no modification or side effects.
Attacks that exploit this kind of access
List all supported ETF tickers. It is categorised as a Read tool in the Marketstack MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Marketstack MCP Server MCP server in PolicyLayer and add a rule for list_etf_tickers: 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 Marketstack MCP Server. Nothing to install.
list_etf_tickers 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 list_etf_tickers 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 list_etf_tickers. 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.
list_etf_tickers is provided by the Marketstack MCP Server MCP server (matteoantoci/mcp-marketstack). 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 →