AI agents call listNodes to retrieve information from Sketch without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves or queries data from Sketch design files with no side effects. It returns information about nodes (design elements) and allows filtering criteria, but does not create, modify, delete, or execute operations. The blast radius is minimal as misuse would only expose or return design data already in the file.
From the tool's definition Tool name 'listNodes' combined with description 'List nodes with optional filtering' indicates a query/retrieval operation. The verb 'list' and 'filtering' are characteristic of Read operations that retrieve data without modification.
Documented attack patterns abuse exactly the kind of access listNodes gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Sketch, and nothing reaches the server without passing your rules. This is the rule we recommend for listNodes:
{
"version": "1",
"default": "deny",
"tools": {
"listNodes": {}
}
}listNodes is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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List nodes with optional filtering. It is categorised as a Read tool in the Sketch MCP Server, which means it retrieves data without modifying state.
Register the Sketch MCP server in PolicyLayer and add a rule for listNodes: 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 Sketch. Nothing to install.
listNodes 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 listNodes 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 listNodes. 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.
listNodes is provided by the Sketch MCP server (mater1996/sketch-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Sketch, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
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17 Sketch tools catalogued and risk-classified — across an index of 43,000+ MCP servers.