AI agents use open_notebook to create or update resources in SiYuan MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your SiYuan MCP Server environment.
Opening a notebook changes the state of the application by making a notebook active/accessible. This is a reversible state change (it can be closed again), making it a Write operation. The sibling tool 'close_notebook' confirms this is a togglable state. Severity is low as misuse has minimal blast radius — it simply opens a notebook.
From the tool's definition 打开指定笔记本 (Open specified notebook)
Documented attack patterns abuse exactly the kind of access open_notebook gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and SiYuan MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for open_notebook:
{
"version": "1",
"default": "deny",
"tools": {
"open_notebook": {
"limits": [
{
"counter": "open_notebook_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}open_notebook stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
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打开指定笔记本. It is categorised as a Write tool in the SiYuan MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the SiYuan MCP Server MCP server in PolicyLayer and add a rule for open_notebook: 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 SiYuan MCP Server. Nothing to install.
open_notebook is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the open_notebook 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 open_notebook. 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.
open_notebook is provided by the SiYuan MCP Server MCP server (xgq18237/siyuan_mcp_server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 52 SiYuan MCP Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
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52 SiYuan MCP Server tools catalogued and risk-classified — across an index of 42,500+ MCP servers.