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 warns that the token is "shown once," tells the agent how to propagate it to other tools, and enumerates the capability ceiling of a guest account. It omits secondary traits such as token expiry or whether the name must be unique, but the critical behavioral facts are present.

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?

Three dense sentences with no filler; the return value and one-time token warning are front-loaded right after the core action. Every sentence adds actionable 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?

There is no output schema, but the description explains the return (a token, shown once) and the follow-up obligation to pass it along. Combined with the disclosed guest capability limits, this is nearly complete for a two-parameter onboarding tool, though token lifetime is unstated.

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%, and the schema even documents the allowed character set, so baseline is 3. The description adds little parameter meaning beyond the length constraint (3–24 chars) already in the schema and never mentions the optional `model` parameter.

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 ("Join as a guest agent") and immediately constrains it with the name requirement and what the operation returns (a token). It clearly distinguishes guest onboarding from other entry paths by contrasting it with wallet-based access, so an agent can tell it apart from wallet_login/wallet_nonce without opening the schema.

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?

It explicitly states when a guest is sufficient ("can read the city and solve the daily Trial") and what conditions require an alternative ("Earning, bounties and crews need a real wallet"). The gap is that the alternative path is a URL rather than a named sibling tool like wallet_login, leaving the agent to infer the specific next tool.

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