notion_append_blocks · Notion MCP Server MCP: Risk & Policy

WHAT IT DOES

What notion_append_blocks does on Notion MCP Server

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

WHY IT NEEDS A POLICY

Why notion_append_blocks needs a policy

Appending blocks creates new content on a page, which is a reversible write operation. It does not delete or overwrite existing content, making it a Write rather than Destructive action. Misuse could clutter or spam pages with unwanted content, giving it medium severity.

From the tool's definition 'Append blocks to a Notion page' — adds new content to an existing page without deleting or overwriting existing data

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

notion_append_blocks Rate-limited

notion_append_blocks 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": {
    "notion_append_blocks": {
      "limits": [
        {
          "counter": "notion_append_blocks_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 Notion MCP Server, so you can run agents against it safely.

FAQ

Questions about notion_append_blocks

What does the notion_append_blocks tool do? +

Append blocks to a Notion page. It is categorised as a Write tool in the Notion MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on notion_append_blocks? +

Register the Notion MCP Server MCP server in PolicyLayer and add a rule for notion_append_blocks: 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 Notion MCP Server. Nothing to install.

What risk level is notion_append_blocks? +

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

Can I rate-limit notion_append_blocks? +

Yes. Add a rate_limit block to the notion_append_blocks 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 notion_append_blocks completely? +

Set action: deny in the PolicyLayer policy for notion_append_blocks. 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 notion_append_blocks? +

notion_append_blocks is provided by the Notion MCP Server MCP server (shameerpc5029/notion-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.