Returns an interval of historical market quotes for any cryptocurrency.
AI agents call cryptoQuotesHistorical 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 historical cryptocurrency price/quote data from CoinMarketCap. It is a read-only query operation with no side effects, no ability to modify market data, and no financial transaction capability. The blast radius of misuse is minimal - an agent could only access historical market information that is already public. Even if repeatedly called, it causes no harm to the system or user accounts.
From the tool's definition Tool returns historical market quotes without modifying data or executing external operations. Description explicitly states it 'Returns' data, with no mention of creating, modifying, deleting, or executing any operations.
Documented attack patterns abuse exactly the kind of access cryptoQuotesHistorical 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 cryptoQuotesHistorical:
{
"version": "1",
"default": "deny",
"tools": {
"cryptoQuotesHistorical": {}
}
}cryptoQuotesHistorical is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Returns an interval of historical market quotes for any cryptocurrency. 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 cryptoQuotesHistorical: 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.
cryptoQuotesHistorical 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 cryptoQuotesHistorical 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 cryptoQuotesHistorical. 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.
cryptoQuotesHistorical 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.