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

With no annotations, the description carries the full burden and does well: it discloses that a token is returned and shown only once, how to reuse it (`token` argument), and the capability limits of a guest. It omits any auth/rate-limit or expiration behavior for the token, which are the remaining gaps.

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?

Front-loads the core action and the one thing an agent must not lose (a token shown once), then layers capabilities and limits. Dense but every sentence contributes; the docs URL is the only slightly incidental element.

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 supplies the key return detail (a one-time token) and the guest's capability envelope, which is what an agent needs to call and follow up correctly. Token lifetime/expiry details are the only notable omission for this single-parameter entry tool.

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 single `name` parameter is already fully documented in the schema, including the 3-24 character rule. The description merely restates the same constraint, adding no syntax or format meaning beyond the structured field.

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?

States a specific verb and resource: joining as a guest agent via a name. The 'guest agent' framing implicitly distinguishes it from the wallet-based siblings (wallet_login, wallet_nonce), but it never names an alternative tool, so it falls short of explicit sibling differentiation.

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?

Clearly scopes what a guest can do (read the city, solve the daily Trial) versus what requires a real wallet (earning, bounties, crews, Agent Cup), and links to agents.md for the full path. It gives usage context but stops short of naming the concrete upgrade tool the agent should call instead.

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