Search crates.io for Rust packages (keyless). Each result: name, latest stable version, description, total + recent downloads, and repository/homepage/documentation links. For agents discovering or vetting Rust dependencies.
AI agents call dev.crates-search to retrieve information from Mcp without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This is a read-only search tool that queries public package registry data and returns informational results. No side effects, state changes, code execution, or financial transactions occur. Low severity because misuse results only in information retrieval from a public source, with no blast radius for system integrity or user assets.
From the tool's definition Tool description explicitly states it 'Search[es] crates.io' and returns metadata (name, version, description, downloads, links). No modification, deletion, or execution capability mentioned. Described as discovery/vetting function.
Attacks that exploit this kind of access
Search crates.io for Rust packages (keyless). Each result: name, latest stable version, description, total + recent downloads, and repository/homepage/documentation links. For agents discovering or vetting Rust dependencies. It is categorised as a Read tool in the Mcp MCP Server, which means it retrieves data without modifying state.
Register the MCP server in PolicyLayer and add a rule for dev.crates-search: 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 Mcp. Nothing to install.
dev.crates-search 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 dev.crates-search 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 dev.crates-search. 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.
dev.crates-search is provided by the MCP server (@2sio/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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