update_block_text · Notion Private Api MCP: Risk & Policy

WHAT IT DOES

What update_block_text does on Notion Private Api

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

WHY IT NEEDS A POLICY

Why update_block_text needs a policy

update_block_text modifies existing block content reversibly (text can be edited again), making it Write rather than Destructive. However, severity is high because an AI agent with workspace-wide access could alter critical documentation, code blocks, or other business-critical content at scale without user oversight.

From the tool's definition Tool description states it 'Replace[s] the plain text content of a block' — a modification operation. The server context emphasizes 'full read/write access to the entire workspace' with no per-page sharing restrictions.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_block_text Rate-limited

update_block_text 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": {
    "update_block_text": {
      "limits": [
        {
          "counter": "update_block_text_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 Private Api, so you can run agents against it safely.

FAQ

Questions about update_block_text

What does the update_block_text tool do? +

Replace the plain text content of a block (e.g. code block). Inline markdown is NOT parsed — text is stored verbatim. It is categorised as a Write tool in the Notion Private Api MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on update_block_text? +

Register the Notion Private Api MCP server in PolicyLayer and add a rule for update_block_text: 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 Private Api. Nothing to install.

What risk level is update_block_text? +

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

Can I rate-limit update_block_text? +

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

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

update_block_text is provided by the Notion Private Api MCP server (kirvigen/notion-private-api-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.