notion_append_block_children

THE RISK

Medium Risk

Why notion_append_block_children needs a policy

This tool creates new content by appending child blocks to an existing Notion block. It modifies data but in a reversible way (blocks can be deleted afterward), making it a Write operation. Misuse could result in unwanted content being added to Notion pages.

From the tool's definition Append children blocks to a block in Notion

Documented attack patterns abuse exactly the kind of access notion_append_block_children gives an agent:

POLICY

How to control notion_append_block_children

PolicyLayer is an MCP gateway — it sits between your AI agents and Notion MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for notion_append_block_children:

policy.json

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

notion_append_block_children 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.

Create a free account and register Notion MCP Server — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

LIMIT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Notion MCP Server tools

Destructive notion_delete_block Delete a block in Notion. Write notion_create_comment Create a new comment in Notion. Write notion_create_database Create a new database in Notion. Write notion_create_page Create a new page in Notion. Write notion_update_block Update a block in Notion. Write notion_update_database Update a database in Notion. Write notion_update_page Update a page in Notion. Read notion_list_block_children List all children blocks of a block in Notion.

All 21 Notion MCP Server tools →

Write tools on other servers

M-Team MCP Server download_torrent YouTube MCP Server generate_video_title Android Forensics ADB MCP Server combine_reports 0xarchive web3_signup

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Argument validation → Checking tool call arguments against schema and policy before they run.
Scoped token → Per-person credentials that grant a defined subset of servers and tools.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about notion_append_block_children

What does the notion_append_block_children tool do? +

Append children blocks to a block in Notion. 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_block_children? +

Register the Notion MCP Server MCP server in PolicyLayer and add a rule for notion_append_block_children: 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_block_children? +

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

Can I rate-limit notion_append_block_children? +

Yes. Add a rate_limit block to the notion_append_block_children 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_block_children completely? +

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

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

Enforce policy on every Notion MCP Server tool call.

Start from Notion MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →