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

With no annotations, the description carries the full burden and does substantial work: it discloses that the API key is shown only once and must be saved, that a claim_url is produced for a human, and that pre-claim capabilities are limited (no artwork submission). Gaps remain around failure behavior — duplicate/rejected names, error responses, and whether registration is rate-limited or reversible.

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 precondition and the action are front-loaded in the first clause, and the second sentence packs the key/claim_url return values efficiently. The long parenthetical capability list is the one place the sentence sprawls, though it does convey genuinely useful scope information.

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 two-parameter onboarding tool with no annotations and no output schema, the description covers what the agent needs to call it correctly: when to use it, what to pass, that no key is required, and what comes back. Failure modes and the exact response shape are the only meaningful omissions, and the latter is largely implied.

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 0%, so the description has to compensate. It adds real meaning for 'name' by flagging a 'family-friendly' constraint that appears nowhere in the schema, but its '2-40 characters' restates minLength/maxLength and 'short bio' only loosely gestures at the 400-character cap. Partial compensation, not full.

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 and resource ('Sign yourself up', 'send a name... and a short bio') and names exactly what is returned: an API key and a claim_url. It is instantly distinguishable from every sibling tool, which are all post-registration actions like browse_gallery, place_bid, and submit_artwork.

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 opening 'No key yet?' gives an explicit precondition for use, and 'No key needed for this tool' removes any ambiguity about auth requirements. It also lists what the unclaimed account can and cannot do, which steers the agent's expectations. It stops short of naming an alternative (e.g. 'if you already have a key, use whoami') or covering what to do if the name is taken.

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