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

Annotations only declare it is a non-read-only, non-idempotent, non-destructive call; the description far exceeds that by disclosing the api_key is shown once and goes in x-api-key, the claim link is valid 7 days, the key stops working on claim, and how the account behaves until claimed (1 free check/day, 402 payment, claim_required). It even documents the separate deletion flow, giving rich lifecycle context the annotations cannot convey.

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 core (account + api_key + claim link) is front-loaded, but the body is a dense wall of parenthetical run-on sentences that mixes lifecycle, pricing, and deletion details. Every fact is relevant, yet the structure makes the critical first-step information harder to extract than a split into short ordered sentences would.

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 signup tool with no output schema, the description fully covers inputs, the returned fields (api_key, claim.url), the claim lifecycle, pre-claim limits, and even the exit path. Nothing an agent needs to call it and understand the result is missing.

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 already 100%, setting a baseline of 3. The description adds genuine meaning beyond the schema, explaining that the claim link is also sent to the optional email and that the agent name is 'kept on the account', which clarifies each parameter's downstream effect.

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 action (create an agent account) and its immediate output (an api_key plus a claim link), distinguishing it from every other sibling tool, which operate on an already-existing account. An agent can tell this is the bootstrap/entry-point tool without opening any 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?

'No key needed' clearly frames the use case as the first step before any keyed operation, and it names related paths (pay_order, claim_required) for the pre-claim state. It stops short of explicitly stating when-not-to-use or naming the prerequisites in a crisp condition, so it is strong context but not full routing guidance.

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