List user-level libraries saved in ~/.excalidraw/.user-libraries/. Returns { name, path, itemCount } for each.
AI agents call user_library_list to retrieve information from Whiteboard without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This is a read-only operation that queries and enumerates existing library metadata from the user's local Excalidraw directory. It has no side effects, cannot modify state, and poses minimal risk even if called inappropriately by an agent. The blast radius is confined to information disclosure of library names and paths, which are typically not sensitive.
From the tool's definition Tool description explicitly states it "List[s] user-level libraries" and "Returns { name, path, itemCount } for each" — pure data retrieval with no modification, deletion, or execution.
Attacks that exploit this kind of access
List user-level libraries saved in ~/.excalidraw/.user-libraries/. Returns { name, path, itemCount } for each. It is categorised as a Read tool in the Whiteboard MCP Server, which means it retrieves data without modifying state.
Register the Whiteboard MCP server in PolicyLayer and add a rule for user_library_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 Whiteboard. Nothing to install.
user_library_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 user_library_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 user_library_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.
user_library_list is provided by the Whiteboard MCP server (kamiazya/whiteboard). 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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