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

With no annotations, the description carries the full burden, and it does disclose two real behavioral facts: the status stays `pending` until approval, and the key is returned only once. It omits other important traits for a polling endpoint, such as whether an approved response can be re-fetched, expiry behavior, or any rate limits.

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?

Two tight clauses with no filler, and the state progression (`pending` → `approved`) is front-loaded before the key-usage note. The telegraphic style is efficient, though slightly clipped.

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, and the description does cover the meaningful return values (status, api_key). However, for a polling tool it leaves the operational flow undefined: how often to check, what to do while pending, and whether the one-time key can be recovered. Adequate but with clear gaps.

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% and the single `id` parameter is documented in the schema as the value sign_up returned. The description adds nothing further about the parameter, so the baseline of 3 applies.

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 names the two possible outcomes of the check (`pending`, `approved` with `api_key`), which lets an agent infer this polls the status of a prior sign_up. It never states the action in a verb+resource phrase of its own, relying on the name and title to establish that. Clear enough to act on, but sibling differentiation from sign_up is only implicit.

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 only usage sentence tells the agent what to do with the returned key (`Authorization: Bearer …`), not when to call this tool. There is no guidance on polling cadence after sign_up, when to stop calling, or how this relates to the sign_up sibling that produced the `id`.

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