List all SSH private keys in ~/.ssh/ with their type, fingerprint, and whether they are loaded in the agent. Use this to find which keys are available and which ones need to be loaded.
AI agents call ssh_key_list to retrieve information from SSH MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
Even though ssh_key_list only reads data, uncontrolled read access leaks sensitive information and racks up API costs — an agent caught in a retry loop can make thousands of calls a minute without anyone noticing.
Attacks that exploit this kind of access
List all SSH private keys in ~/.ssh/ with their type, fingerprint, and whether they are loaded in the agent. Use this to find which keys are available and which ones need to be loaded. It is categorised as a Read tool in the SSH MCP Server MCP Server, which means it retrieves data without modifying state.
Register the SSH MCP Server MCP server in PolicyLayer and add a rule for ssh_key_list: 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 SSH MCP Server. Nothing to install.
ssh_key_list 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 ssh_key_list 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 ssh_key_list. 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.
ssh_key_list is provided by the SSH MCP Server MCP server (yawlabs/ssh-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.