bookmarks.add · X MCP Server MCP: Risk & Policy

WHAT IT DOES

What bookmarks.add does on X MCP Server

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

WHY IT NEEDS A POLICY

Why bookmarks.add needs a policy

This tool creates a new bookmark record, which is a reversible modification of user data. It does not delete, execute code, or move money, so it falls under Write rather than more severe categories. Severity is medium because misuse could spam a user's bookmarks or bookmark sensitive/inappropriate content, but the action is fully reversible via bookmarks.remove.

From the tool's definition Tool name 'bookmarks.add' and description 'Add a tweet to bookmarks' indicate creation/modification of user data (bookmarks collection). This is a write operation that creates a new association between a user and a tweet.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

bookmarks.add Rate-limited

bookmarks.add 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": {
    "bookmarks.add": {
      "limits": [
        {
          "counter": "bookmarks.add_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 X MCP Server, so you can run agents against it safely.

FAQ

Questions about bookmarks.add

What does the bookmarks.add tool do? +

Add a tweet to bookmarks. It is categorised as a Write tool in the X 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 bookmarks.add? +

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

What risk level is bookmarks.add? +

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

Can I rate-limit bookmarks.add? +

Yes. Add a rate_limit block to the bookmarks.add 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 bookmarks.add completely? +

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

bookmarks.add is provided by the X MCP Server MCP server (tomaitagaki/x-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.