Returns information about all coin categories available on CoinMarketCap.
AI agents call cryptoCategories 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 and lists cryptocurrency categories—purely informational data with no side effects, no code execution, no financial transactions, and no data modification. It is a straightforward Read operation with minimal security risk.
From the tool's definition Returns information about all coin categories available on CoinMarketCap. The verb 'returns' and the passive framing indicate a read-only query operation that retrieves categorical data without modifying, executing, or deleting anything.
Documented attack patterns abuse exactly the kind of access cryptoCategories 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 cryptoCategories:
{
"version": "1",
"default": "deny",
"tools": {
"cryptoCategories": {}
}
}cryptoCategories is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
Free to start. No card required.
Returns information about all coin categories available on CoinMarketCap. 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 cryptoCategories: 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.
cryptoCategories 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 cryptoCategories 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 cryptoCategories. 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.
cryptoCategories 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.