MCP Tool: Appends content to the end of an existing note, with backup option.
AI agents use append_to_note to create or update resources in Obsidian MCP Tool Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Obsidian MCP Tool Server environment.
This tool modifies an existing note by adding content to it. It is a reversible write operation (a backup option is mentioned, implying recovery is possible). It does not delete or overwrite data destructively, execute code, or involve financial transactions.
From the tool's definition Appends content to the end of an existing note, with backup option
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 Tool Server, 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.
MCP Tool: Appends content to the end of an existing note, with backup option. It is categorised as a Write tool in the Obsidian MCP Tool Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Obsidian MCP Tool Server 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 Tool Server. 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 Tool Server MCP server (rwb3n/obsidian-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 18 Obsidian MCP Tool Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
18 Obsidian MCP Tool Server tools catalogued and risk-classified — across an index of 42,500+ MCP servers.