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

Annotations already declare idempotentHint true and readOnlyHint false, but the description adds significant behavioral detail beyond that: the mandatory consent condition ('consent: true is a recorded claim - assert it only with the person's consent'), the idempotent behavior ('repeats return already: true'), and the return of an edit_token for follow-ups. It also indicates the need for agent self-identification, which is not covered by annotations. No contradictions.

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 three sentences, each dense with information: the core action, the consent constraint, the idempotency behavior, the return value, and the self-identification requirement. No filler or repetition. The most critical fact (the join action) is front-loaded.

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?

Despite having no output schema, the description explains the return value (edit_token) and the idempotent response (already: true). It also specifies the consent requirement and the optional identification fields. For a simple join operation, all necessary information to call correctly is present, including behavioral nuances.

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%, so the baseline is 3. The description adds meaning to the consent parameter (a recorded claim requiring the person's consent) and explains the purpose of the three optional self-identification parameters ('Identify yourself with agent_name, agent_operator, on_behalf_of'). It does not elaborate on email beyond that, but the schema covers it.

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 action ('joins the named person to the Clair pilot waitlist') with a specific verb and resource. It also differentiates itself from siblings by noting it is a 'one typed transaction' and that repeats return 'already: true', implying this is for initial signups, distinct from get_signup_schema (schema retrieval) and update_waitlist (modification). No tautology.

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 provides context on when to use it: for a one-time join, and it implies that repeated submissions are handled (returns already: true). It also mentions self-identification for the agent. However, it does not explicitly name the alternative tools or state when NOT to use this tool (e.g., for updates), leaving some inference to the agent.

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