Get a user

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

The annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, and the description's 'Fetch' wording is consistent with a read-only operation. The description does not add behavioral details beyond what annotations provide, but it does not contradict them.

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 concise sentence that front-loads the primary purpose and includes essential identifier context without unnecessary words or repetition.

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?

With no output schema, the description adequately frames the tool as fetching a single user and leaves the details to the parameter schema. It does not explicitly state what fields are returned, but the detail parameter provides a summary/full distinction, and the core intent is fully conveyed.

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 descriptions cover all three parameters with enums, defaults, and inline explanations. The tool description adds meaningful context for the 'external' option by explaining that external IDs are 'carried over from a billing system or a Pterodactyl/Pelican migration', enriching the schema's bare 'external ID' wording.

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 clearly states a specific verb ('Fetch') and resource ('one user'), and distinguishes it from list-oriented siblings by emphasizing retrieval of a single user. It also uniquely specifies the supported identifier types (UUID or external ID), making the tool's purpose unambiguous.

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 provides clear context for when to use the tool: fetching a single user by UUID or external ID. It implicitly distinguishes from list_users and user-specific sub-resources, though it does not explicitly state 'use list_users to browse' or enumerate exclusions.

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