Launch a target stdio MCP server and list its tools. Best for first-pass inspection; if the target has expensive startup or stateful follow-up work, open a wrapper session instead.
AI agents call stdio_mcp_list_tools to retrieve information from MCP Stdio Wrapper without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool is a read-only operation that inspects and enumerates tools exposed by another MCP server. It has no side effects, does not modify data, does not execute arbitrary code, and does not delete or move resources. The description explicitly frames it as 'inspection' for 'first-pass' discovery.
From the tool's definition Tool performs 'list its tools' operation which retrieves and queries available tools from a target stdio MCP server without modifying any state or executing operations.
Attacks that exploit this kind of access
Launch a target stdio MCP server and list its tools. Best for first-pass inspection; if the target has expensive startup or stateful follow-up work, open a wrapper session instead. It is categorised as a Read tool in the MCP Stdio Wrapper MCP Server, which means it retrieves data without modifying state.
Register the MCP Stdio Wrapper MCP server in PolicyLayer and add a rule for stdio_mcp_list_tools: 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 Stdio Wrapper. Nothing to install.
stdio_mcp_list_tools 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 stdio_mcp_list_tools 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 stdio_mcp_list_tools. 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.
stdio_mcp_list_tools is provided by the MCP Stdio Wrapper MCP server (joshuagreeff/mcp-stdio-wrapper). 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.
Teams ship this data inside their own products. See what a licence covers →