Get a user

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds value beyond annotations by noting that the response 'includes roles and a summary of notable capabilities when permitted', which hints at conditional content based on permissions. This is useful context not present in the 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 efficient sentence that front-loads the action and resource, then adds the special 'me' case and the response content. There is no fluff or redundancy, and every phrase adds relevant detail.

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?

For a simple fetch tool with full schema coverage and readOnly annotations, the description covers the key behavior: how to fetch, the 'me' special case, and what extra info is returned. It does not describe the response envelope (e.g., whether it returns a full user object), but given the simplicity and the absence of an output schema, this is not a significant gap.

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 description coverage is 100%, so the schema fully documents both parameters. The description adds no new parameter semantics beyond the schema's own description of 'id' and 'site_id'. It merely restates the 'by ID' concept, so it does not compensate or extend the schema's completeness.

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 states a specific verb ('Fetch') and a specific resource ('one user'), and distinguishes the special 'me' case. It clearly differentiates from sibling tools like list_users, create_user, and update_user by focusing on a single-user retrieval with roles and capabilities.

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 implies usage context: use when you need a single user by ID or the authenticated user. It does not explicitly contrast with list_users or other alternatives, but the singular fetch nature is clear. A minor gap is the absence of an explicit 'use this instead of X' statement.

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