profileFetch a Minecraft player's public profile by UUID via Mojang Session Server; returns current username and skin/cape texture URLs.
| Name | Required | Description | Default |
|---|---|---|---|
| uuid | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
| id | Yes | UUID of the player | |
| name | Yes | Username of the player | |
| properties | Yes | Player profile properties including textures |
Changes observed during successful MCP inspections.
Input schema / examplesAdded value: +[
+ {
+ "uuid": "069a79f4-44e9-405c-b647-db3f2e3f5e88"
+ }
+]Output schema / (root)Previous value: -nullNew value: +{
+ "properties": {
+ "id": {
+ "description": "UUID of the player",
+ "type": "string"
+ },
+ "name": {
+ "description": "Username of the player",
+ "type": "string"
+ },
+ "properties": {
+ "description": "Player profile properties including textures",
+ "items": {
+ "properties": {
+ "name": {
+ "description": "Property name",
+ "type": "string"
+ },
+ "signature": {
+ "description": "Cryptographic signature of the property",
+ "type": "string"
+ },
+ "value": {
+ "description": "Property value",
+ "type": "string"
+ }
+ },
+ "type": "object"
+ },
+ "type": "array"
+ }
+ },
+ "required": [
+ "id",
+ "name",
+ "properties"
+ ],
+ "type": "object"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, covering safety. The description adds context that the data comes from an external Mojang Session Server and that the profile is public, which is marginally useful. However, it does not discuss rate limits, failure modes, or other behavioral quirks, so it adds only limited value beyond annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single, front-loaded sentence that gets straight to the action ('Fetch'), specifies the resource and input, and notes the output. Every word earns its place with no redundancy or filler.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the tool's simplicity (one parameter, no nested objects) and the presence of an output schema, the description covers the essential aspects: purpose, input semantics, data source, and return type. It is sufficient for an agent to select and invoke the tool correctly.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 0% because the uuid property has no description. The tool description compensates by stating that the parameter is a Minecraft player's UUID, directly linking it to the 'Fetch by UUID' behavior. This adds meaningful semantics beyond the bare 'string' type in the schema.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description uses a specific verb 'Fetch' and identifies a precise resource: 'a Minecraft player's public profile by UUID via Mojang Session Server'. It also states the return value ('current username and skin/cape texture URLs'), which clearly distinguishes it from sibling tools like username_to_uuid or name_history.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description clearly implies the use case: when you have a UUID and want the current public profile of a Minecraft player. It does not explicitly name alternatives or exclusions, but the context is clear enough to guide an agent. Sibling tools such as username_to_uuid serve a different purpose, so the tool's role is unambiguous.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.