mastodon-mcp-server

Instance Info

instance_info

Read-onlyIdempotent

Retrieve details about the connected Mastodon instance, including its name, description, version, and rules, to understand the server you are interacting with.

Instructions

Get information about the connected Mastodon instance.

Returns: str: JSON with instance name, description, version, rules, etc.

Input Schema

TableJSON Schema

Name	Required	Description	Default
No arguments

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

A3.9/5.0

Behavior3/5

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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=true and destructiveHint=false, so the safety and repeatability profile is covered. The description adds only the returned content shape (name, description, version, rules) and says nothing about authentication needs, rate limits, or freshness, so it adds modest value beyond structured fields.

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?

Front-loaded with the operation, then a short returns note; nothing extraneous. The 'Returns:' block is mildly redundant given a dedicated output schema exists, which keeps it just short of ideal.

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?

With an output schema present and annotations covering the safety profile, the description need not explain return values, and it still does so briefly. Purpose and expected payload are clear; only explicit usage context is missing, which is minor for a single unambiguous tool.

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

Parameters4/5

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

The tool takes zero parameters, so there is nothing for the description to disambiguate. The baseline for a parameterless tool applies.

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?

States a specific verb and resource ('Get information about the connected Mastodon instance') that unambiguously identifies the tool. No sibling in the list covers instance-level metadata (all others target accounts, statuses, lists, notifications, etc.), so the distinction is automatic.

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

Usage Guidelines3/5

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

There is no explicit when-to-use guidance (e.g., to discover the server version for feature compatibility) and no mention of alternatives. However, because this is the only instance-scoped tool and its name/purpose are self-evident, usage is strongly implied rather than misleading.

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

Deploy Server