mastodon-mcp-server

Account Block

account_block

Idempotent

Block a Mastodon account by numeric ID to prevent unwanted interactions and stop seeing its posts.

Instructions

Block an account.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`account_id`	Yes	Numeric account ID to block.

Output Schema

TableJSON Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed2 schema fields changedv1.0.5Sep 12, 2026

addedInput schema / additionalProperties
```
Added value: +false
```

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "properties": {
+    "result": {
+      "type": "string"
+    }
+  },
+  "required": [
+    "result"
+  ],
+  "type": "object",
+  "x-fastmcp-wrap-result": true
+}

First observedv1.0.1Jun 26, 2026

TDQS

C2.9/5.0

Behavior2/5

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

Annotations already declare this is a non-read-only, idempotent, non-destructive, open-world operation, so safety is partly covered. However, the description adds nothing about actual effects on the target account (relationship changes, visibility, reversibility), which is exactly the context a caller needs for a mutating account action.

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

Conciseness4/5

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

One sentence with no filler and the action front-loaded; nothing is redundant. It is efficient, though arguably too terse to be maximally useful.

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

Completeness3/5

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

An output schema exists, so return values need not be explained, and the single parameter is fully documented. Still missing are the operational consequences of blocking and whether it can target the authenticated account, leaving the definition minimally adequate for a mutation tool.

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% and the single account_id parameter is documented in the schema as a numeric account ID. The description adds no extra meaning, so the baseline of 3 applies when the schema carries the load.

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

Purpose4/5

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

The description gives a concrete verb and resource ("Block an account"), which is unambiguous on its own. It does not, however, distinguish this from adjacent siblings like account_unblock or account_mute, so the agent must infer the direction from the name alone.

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

Usage Guidelines2/5

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

There is no guidance on when to block versus mute or unfollow, no mention of the inverse tool account_unblock, and no stated preconditions. The agent gets no routing help beyond the tool name.

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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