Returns a paginated list of all active cryptocurrencies with latest market data
AI agents call listing-coins to retrieve information from Coin 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 cryptocurrency listing and market data from CoinMarketCap without any side effects. It performs a read-only query operation that does not create, modify, delete, or execute code. The paginated list format is typical of data retrieval endpoints. No financial transactions occur, and no irreversible actions are performed.
From the tool's definition Tool returns a paginated list of cryptocurrencies with market data; description contains 'Returns' indicating data retrieval with no modification or deletion capability.
Documented attack patterns abuse exactly the kind of access listing-coins gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Coin MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for listing-coins:
{
"version": "1",
"default": "deny",
"tools": {
"listing-coins": {}
}
}listing-coins is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Returns a paginated list of all active cryptocurrencies with latest market data. It is categorised as a Read tool in the Coin MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Coin MCP Server MCP server in PolicyLayer and add a rule for listing-coins: 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 Coin MCP Server. Nothing to install.
listing-coins 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 listing-coins 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 listing-coins. 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.
listing-coins is provided by the Coin MCP Server MCP server (longmans/coin_api_mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Coin MCP Server, 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.
3 Coin MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.