Write or update a note. For tag-only updates, use update_tags instead
AI agents use write_note to create or update resources in Obsidian Ai Curator — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Obsidian Ai Curator environment.
This tool creates new notes or modifies existing ones in the user's Obsidian vault. These are reversible operations (notes can be edited or deleted later), placing it in the Write category. Severity is high because an AI agent with unconstrained access could create, overwrite, or flood the vault with unintended notes, potentially corrupting important knowledge base entries or displacing critical information.
From the tool's definition Tool description explicitly states 'Write or update a note' — creates or modifies data in the Obsidian vault reversibly. Name 'write_note' and description confirm Create/Update semantics.
Documented attack patterns abuse exactly the kind of access write_note gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Obsidian Ai Curator, and nothing reaches the server without passing your rules. This is the rule we recommend for write_note:
{
"version": "1",
"default": "deny",
"tools": {
"write_note": {
"limits": [
{
"counter": "write_note_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}write_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.
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Write or update a note. For tag-only updates, use update_tags instead. It is categorised as a Write tool in the Obsidian Ai Curator MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Obsidian Ai Curator MCP server in PolicyLayer and add a rule for write_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 Ai Curator. Nothing to install.
write_note 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 write_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.
Set action: deny in the PolicyLayer policy for write_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.
write_note is provided by the Obsidian Ai Curator MCP server (nwant/obsidian-ai-curator). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Obsidian Ai Curator, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
27 Obsidian Ai Curator tools catalogued and risk-classified — across an index of 43,000+ MCP servers.