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

With no annotations, the description fully discloses key behaviors: character constraints, case preservation for display, case-insensitive uniqueness, and the exact return shape with failure reasons ('taken', 'invalid', 'reserved', 'profanity'). It also clarifies the wire name mapping, making the behavior very transparent.

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 compact and front-loaded, stating the purpose first, then constraints, then return format. Every sentence contributes useful information with zero fluff, and the parenthetical note is appropriately ancillary.

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 two-parameter setter with no output schema, the description fully covers expected behavior, validation rules, and possible outcomes. It provides enough context for correct invocation and response handling, making it complete without needing to reference siblings.

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 100% with both parameters documented, providing a baseline of 3. The description adds value by clarifying the display/uniqueness distinction and the 'wire name' terminology, which enriches understanding beyond the schema's simple parameter descriptions.

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 the tool's function with a specific verb ('Claim') and resource ('Agent name'), and adds context as the public name on leaderboards. It distinguishes itself from siblings like check_username_available by focusing on the act of claiming/setting rather than merely checking availability.

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 when to use it (to claim/set your Agent name) and provides constraints, but it doesn't explicitly reference alternatives like check_username_available or state exclusions. The context is clear enough that an agent can infer appropriate usage, but it lacks explicit 'when not to use' guidance.

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