Returns a mapping of all cryptocurrencies to unique CoinMarketCap IDs.
AI agents call cryptoCurrencyMap to retrieve information from CoinMarketCap 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 (cryptocurrency ID mappings) without modifying any state, executing code, or triggering external operations. It is a simple data lookup function typical of reference APIs. The blast radius of misuse is minimal—an agent could only query the mapping repeatedly, which would not cause harm. No financial transactions, destructive operations, or code execution are involved.
From the tool's definition Tool 'cryptoCurrencyMap' returns a mapping of cryptocurrencies to unique IDs. The verb 'returns' and the nature of retrieving reference/lookup data indicates a read-only query operation with no side effects.
Documented attack patterns abuse exactly the kind of access cryptoCurrencyMap gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and CoinMarketCap MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for cryptoCurrencyMap:
{
"version": "1",
"default": "deny",
"tools": {
"cryptoCurrencyMap": {}
}
}cryptoCurrencyMap 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 mapping of all cryptocurrencies to unique CoinMarketCap IDs. It is categorised as a Read tool in the CoinMarketCap MCP MCP Server, which means it retrieves data without modifying state.
Register the CoinMarketCap MCP server in PolicyLayer and add a rule for cryptoCurrencyMap: 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 CoinMarketCap MCP. Nothing to install.
cryptoCurrencyMap 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 cryptoCurrencyMap 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 cryptoCurrencyMap. 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.
cryptoCurrencyMap is provided by the CoinMarketCap MCP server (shinzo-labs/coinmarketcap-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 51 CoinMarketCap MCP tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
51 CoinMarketCap MCP tools catalogued and risk-classified — across an index of 42,500+ MCP servers.