list_accounts_add · Mastodon MCP: Risk & Policy

WHAT IT DOES

What list_accounts_add does on Mastodon

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

WHY IT NEEDS A POLICY

Why list_accounts_add needs a policy

This tool modifies list membership by adding accounts to a list. This is a reversible write operation (accounts can be removed from lists), so it falls under Write rather than Destructive. Misuse could lead to unwanted list membership changes but has limited blast radius.

From the tool's definition "Add accounts to a list" - creates a new association between accounts and a list

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

list_accounts_add Rate-limited

list_accounts_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": {
    "list_accounts_add": {
      "limits": [
        {
          "counter": "list_accounts_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 Mastodon, so you can run agents against it safely.

FAQ

Questions about list_accounts_add

What does the list_accounts_add tool do? +

Add accounts to a list. It is categorised as a Write tool in the Mastodon MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on list_accounts_add? +

Register the Mastodon MCP server in PolicyLayer and add a rule for list_accounts_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 Mastodon. Nothing to install.

What risk level is list_accounts_add? +

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

Can I rate-limit list_accounts_add? +

Yes. Add a rate_limit block to the list_accounts_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 list_accounts_add completely? +

Set action: deny in the PolicyLayer policy for list_accounts_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 list_accounts_add? +

list_accounts_add is provided by the Mastodon MCP server (vitexsoftware/mastodon-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.