AI agents use add-note to create or update resources in MCP Notes Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your MCP Notes Server environment.
The tool creates new data (a note) without permanent deletion or irreversible consequences. It is reversible via the 'delete-note' sibling tool. This is a standard Write operation. Severity is low because note creation has minimal blast radius—the worst case is cluttering a notes database with unwanted entries, which can be undone.
From the tool's definition Tool name is 'add-note' and description states 'Create a new note'. This is a create operation that modifies data (adds a new note) reversibly.
Documented attack patterns abuse exactly the kind of access add-note gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and MCP Notes Server, and nothing reaches the server without passing your rules. This is the rule we recommend for add-note:
{
"version": "1",
"default": "deny",
"tools": {
"add-note": {
"limits": [
{
"counter": "add-note_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}add-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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Create a new note. It is categorised as a Write tool in the MCP Notes Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the MCP Notes Server MCP server in PolicyLayer and add a rule for add-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 MCP Notes Server. Nothing to install.
add-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 add-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 add-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.
add-note is provided by the MCP Notes Server MCP server (truaxki/mcp-notes). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from MCP Notes Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
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4 MCP Notes Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.