create_book_note

THE RISK

Medium Risk

Why create_book_note needs a policy

This tool creates new note content in the vault, which is a reversible write operation. It does not execute code, delete data, or trigger external side effects. The severity is low because note creation in a personal knowledge management system like Obsidian has minimal blast radius—notes can be edited or deleted.

From the tool's definition Tool name 'create_book_note' and description 'Structured book/literature note' indicate creation of a new note document in the Obsidian vault. The verb 'create' and the context of note creation systems establish a Write operation.

Documented attack patterns abuse exactly the kind of access create_book_note gives an agent:

POLICY

How to control create_book_note

PolicyLayer is an MCP gateway — it sits between your AI agents and Obsidian MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for create_book_note:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "create_book_note": {
      "limits": [
        {
          "counter": "create_book_note_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

create_book_note 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.

Create a free account and register Obsidian MCP Server — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

LIMIT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Obsidian MCP Server tools

Destructive cleanup_broken_references Remove/fix broken links Destructive delete_attachment Remove attachment file Destructive delete_note Delete a note from the vault Execute execute_dataview_query Run Dataview DQL query and return results Write remove_tags Remove tags from an existing note Write regex_search_and_replace Find and replace with regex across vault Write add_card_to_canvas Add text/note/media card to canvas Write add_connection_to_canvas Connect cards with lines/arrows

All 120 Obsidian MCP Server tools →

Write tools on other servers

M-Team MCP Server download_torrent YouTube MCP Server generate_video_title Android Forensics ADB MCP Server combine_reports 0xarchive web3_signup

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Argument validation → Checking tool call arguments against schema and policy before they run.
Scoped token → Per-person credentials that grant a defined subset of servers and tools.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about create_book_note

What does the create_book_note tool do? +

Structured book/literature note. It is categorised as a Write tool in the Obsidian MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on create_book_note? +

Register the Obsidian MCP Server MCP server in PolicyLayer and add a rule for create_book_note: 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 Obsidian MCP Server. Nothing to install.

What risk level is create_book_note? +

create_book_note is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit create_book_note? +

Yes. Add a rate_limit block to the create_book_note 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.

How do I block create_book_note completely? +

Set action: deny in the PolicyLayer policy for create_book_note. 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.

What MCP server provides create_book_note? +

create_book_note is provided by the Obsidian MCP Server MCP server (kynlos/obsidian-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Obsidian MCP Server tool call.

Start from Obsidian MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →