add_note · MCPHub MCP: Risk & Policy

WHAT IT DOES

What add_note does on MCPHub

AI agents use add_note to create or update resources in MCPHub — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your MCPHub environment.

WHY IT NEEDS A POLICY

Why add_note needs a policy

This tool creates or appends data to files, which is a reversible write operation. It does not delete data (would be Destructive), execute arbitrary code (would be Execute), or move money (would be Financial). The severity is medium because uncontrolled note-adding could result in file bloat, overwriting important content, or writing sensitive data to unexpected locations, but the operation remains reversible.

From the tool's definition Tool name 'add_note' and description '将笔记添加到指定文件中' (add notes to a specified file) indicate creation/modification of data in files.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_note Rate-limited

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.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "add_note": {
      "limits": [
        {
          "counter": "add_note_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches MCPHub, so you can run agents against it safely.

FAQ

Questions about add_note

What does the add_note tool do? +

将笔记添加到指定文件中。. It is categorised as a Write tool in the MCPHub MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on add_note? +

Register the MCPHub 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 MCPHub. Nothing to install.

What risk level is add_note? +

add_note is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit add_note? +

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.

How do I block add_note completely? +

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.

What MCP server provides add_note? +

add_note is provided by the MCPHub MCP server (jayden-dong/mcphub). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.