Search for Crow users by email hash. Privacy-preserving: only SHA-256 hashes are compared, never plain text emails. Users must opt in to discovery by setting their email hash.
AI agents call crow_find_contacts 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 retrieves or queries contact data based on a privacy-preserving hashed lookup. It has no side effects—it does not create, modify, delete, execute code, or move money. The opt-in and hash-only design mitigate privacy risks, though an AI agent could theoretically enumerate users if given multiple hashes.
From the tool's definition Tool performs a 'Search' operation for Crow users by email hash comparison. The description explicitly states it 'Search[es] for Crow users' and only 'compares' hashes—no data modification, deletion, or execution occurs.
Documented attack patterns abuse exactly the kind of access crow_find_contacts 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_find_contacts:
{
"version": "1",
"default": "deny",
"tools": {
"crow_find_contacts": {}
}
}crow_find_contacts is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Search for Crow users by email hash. Privacy-preserving: only SHA-256 hashes are compared, never plain text emails. Users must opt in to discovery by setting their email hash. 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_find_contacts: 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_find_contacts 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_find_contacts 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_find_contacts. 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_find_contacts 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.
Free to start. No card required.
576 Crow tools catalogued and risk-classified — across an index of 43,000+ MCP servers.