mastodon-mcp

Block a whole instance

block_domain

Destructive

Hide all accounts from a domain and remove their followers. Use when an entire instance is a persistent problem. Requires explicit confirmation.

Instructions

Hide every account on an entire instance and remove their followers. This is the blunt instrument for a server that is a persistent problem rather than one account. Needs confirm: true.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "domain": "<domain>"
    },
    "name": "block_domain"
  }
}

Input Schema

Name	Required	Description
`domain`	Yes	Bare hostname, e.g. spam.example.
`account`	No	Which connected account to act as. Matches a full handle (alice@example.social), a bare username (alice), or an instance (example.social). Defaults to the first connected account. Call list_accounts to see them.
`confirm`	No	Must be true for this to run. The result is public immediately or cannot be undone, so it is refused without an explicit confirmation.

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0Sep 2, 2026

TDQS

A4.2/5.0

Behavior4/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already carry destructiveHint=true and readOnlyHint=false. The description adds concrete behavioral context beyond that: it hides entire instance accounts and removes followers, and it flags the confirmation requirement.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is two concise sentences plus a short confirmation note. Every part earns its place: the action, the usage context, and the confirmation requirement.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

It communicates scope, purpose, and confirmation need, and the schema handles parameter details. It does not describe the return value or reversibility, but the destructive annotation and confirm flag make the operation adequately clear.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema already fully documents domain, account, and confirm. The description only mentions confirm, adding no meaningful parameter semantics beyond the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description says exactly what the tool does: hide every account on an instance and remove their followers. It further distinguishes this from a single-account action with 'rather than one account', making it clear versus sibling tools like block_account.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

It gives a clear usage condition: use this when a server is a persistent problem rather than one account. It does not explicitly name alternative tools or state when not to use it, so it is slightly below a 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

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