List all kernels currently tracked in this session, with their status
AI agents call kernel_list to retrieve information from JupyterMCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves and queries the status of kernels without modifying, deleting, or executing operations. It has no side effects beyond returning information. The verb 'list' and the read-only nature of status reporting place it firmly in the Read category with low severity.
From the tool's definition Tool name 'kernel_list' and description 'List all kernels currently tracked in this session, with their status' indicate retrieval of information only.
Attacks that exploit this kind of access
List all kernels currently tracked in this session, with their status. It is categorised as a Read tool in the JupyterMCP MCP Server, which means it retrieves data without modifying state.
Register the Jupyter MCP server in PolicyLayer and add a rule for kernel_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 JupyterMCP. Nothing to install.
kernel_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 kernel_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 kernel_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.
kernel_list is provided by the Jupyter MCP server (try3d/jupytermcp). 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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