AI agents call crow_list_songs to retrieve information from Crow without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool queries and retrieves data (songs from a songbook) without creating, modifying, deleting, or executing external operations. It is a straightforward read operation with minimal blast radius if misused by an AI agent.
From the tool's definition Tool name contains 'list' and description states 'List songs in the songbook' — a retrieval operation with no modification or side effects.
Documented attack patterns abuse exactly the kind of access crow_list_songs gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Crow, and nothing reaches the server without passing your rules. This is the rule we recommend for crow_list_songs:
{
"version": "1",
"default": "deny",
"tools": {
"crow_list_songs": {}
}
} crow_list_songs is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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List songs in the songbook. It is categorised as a Read tool in the Crow MCP Server, which means it retrieves data without modifying state.
Register the Crow MCP server in PolicyLayer and add a rule for crow_list_songs: 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 Crow. Nothing to install.
crow_list_songs 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 crow_list_songs 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 crow_list_songs. 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.
crow_list_songs is provided by the Crow MCP server (kh0pper/crow). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Crow, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
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576 Crow tools catalogued and risk-classified — across an index of 43,000+ MCP servers.