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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description's 'Return' aligns with a read-only lookup. It adds value by explaining how identity is resolved (via OAuth bearer or an auth_token), which annotations do not cover.

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?

One sentence with the action front-loaded and no fluff. The parenthetical auth detail is compact and directly relevant.

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 one-parameter read-only tool with an output schema and safety annotations, the description covers the necessary behavioral context. It does not need to restate return values or elaborate on error conditions.

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?

The input schema has 0% description coverage, so the description must compensate. It mentions 'auth_token' in prose, but does not explain its meaning, optionality, or interplay with OAuth bearer, leaving the schema's default null as the only structural clue.

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 'Return the current logged-in user', naming a specific verb and resource. It also adds the auth context (OAuth bearer or auth_token), which distinguishes it from siblings like login and get_entitlements.

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 use when the agent needs to identify the currently authenticated user, providing clear context without naming exclusions or alternatives. The auth-method note gives practical guidance on how the tool operates.

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