Append text to the end of an existing note without altering prior content. By default, inserts a leading newline if the file does not already end in one, so appended content starts on its own line. Use for log entries, running lists, or adding new sections. Fails if the note does not exist — use ...
AI agents use append_to_note to create or update resources in Obsidian Mcp Pro — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Obsidian Mcp Pro environment.
This tool modifies an existing note by adding content to it. It is a write operation (non-destructive append) that changes vault data reversibly — the appended text could be removed. Severity is medium because an AI agent could pollute or corrupt note content at scale across a vault, but the operation does not delete or overwrite existing content.
From the tool's definition Append text to the end of an existing note without altering prior content
Documented attack patterns abuse exactly the kind of access append_to_note gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Obsidian Mcp Pro, and nothing reaches the server without passing your rules. This is the rule we recommend for append_to_note:
{
"version": "1",
"default": "deny",
"tools": {
"append_to_note": {
"limits": [
{
"counter": "append_to_note_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}append_to_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.
Append text to the end of an existing note without altering prior content. By default, inserts a leading newline if the file does not already end in one, so appended content starts on its own line. Use for log entries, running lists, or adding new sections. Fails if the note does not exist — use create_note to make a new note first. It is categorised as a Write tool in the Obsidian Mcp Pro MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Obsidian Mcp Pro MCP server in PolicyLayer and add a rule for append_to_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 Pro. Nothing to install.
append_to_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 append_to_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 append_to_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.
append_to_note is provided by the Obsidian Mcp Pro MCP server (rps321321/obsidian-mcp-pro). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Obsidian Mcp Pro, 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.
41 Obsidian Mcp Pro tools catalogued and risk-classified — across an index of 43,000+ MCP servers.