Headless-guarded filesystem note update. Supports filePath targets with append or prepend. Uses atomic writes and vault path safety.
AI agents use obsidian_update_note to create or update resources in Optimike Obsidian MCP — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Optimike Obsidian MCP environment.
The tool modifies note content through append/prepend operations, which are Write operations (creates or modifies data reversibly). It is not Destructive because updates are reversible and do not permanently delete data.
From the tool's definition Tool name includes 'update' and description states 'note update' with 'append or prepend' operations on filesystem targets. These are reversible modifications to existing data.
Documented attack patterns abuse exactly the kind of access obsidian_update_note gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Optimike Obsidian MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for obsidian_update_note:
{
"version": "1",
"default": "deny",
"tools": {
"obsidian_update_note": {
"limits": [
{
"counter": "obsidian_update_note_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}obsidian_update_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.
Free to start. No card required.
Headless-guarded filesystem note update. Supports filePath targets with append or prepend. Uses atomic writes and vault path safety. It is categorised as a Write tool in the Optimike Obsidian MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Optimike Obsidian MCP server in PolicyLayer and add a rule for obsidian_update_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 Optimike Obsidian MCP. Nothing to install.
obsidian_update_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 obsidian_update_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 obsidian_update_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.
obsidian_update_note is provided by the Optimike Obsidian MCP server (optimikelabs/optimike-obsidian-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Optimike Obsidian MCP, 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.
15 Optimike Obsidian MCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.