List all available MCP backend servers. Call this first to discover what servers and capabilities are available before loading any.
AI agents call gateway_list_servers to retrieve information from MCP Gateway without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool queries the state of available backend servers and returns metadata about them. It has no side effects, creates no data, executes no code, and makes no modifications. It is purely informational enumeration, which is the lowest-risk category. The low severity reflects that discovering available services poses minimal security risk in isolation.
From the tool's definition Tool name is 'gateway_list_servers' and description states 'List all available MCP backend servers.' The verb 'list' and the action of discovering/enumerating available servers without modification are characteristic of a Read operation.
Attacks that exploit this kind of access
List all available MCP backend servers. Call this first to discover what servers and capabilities are available before loading any. It is categorised as a Read tool in the MCP Gateway MCP Server, which means it retrieves data without modifying state.
Register the MCP Gateway MCP server in PolicyLayer and add a rule for gateway_list_servers: 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 Gateway. Nothing to install.
gateway_list_servers 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 gateway_list_servers 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 gateway_list_servers. 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.
gateway_list_servers is provided by the MCP Gateway MCP server (raiansar/mcp-gateway). 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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