account_options

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

With no annotations, the description carries the full burden. It discloses that the call is unauthenticated and fully specifies the return shape (dict keys). It does not explicitly declare side-effect-free behavior, but the read-only nature is strongly implied by the content and the 'before start_checkout' guidance.

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?

At three short sentences plus a key list, the description is appropriately compact and front-loads the core answer (returned fields) before usage guidance. The opening is a slight sentence fragment, but it is not padded and every line contributes.

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 parameterless tool with no output schema and no annotations, the description is fairly complete: it covers when to call, authentication status, and the exact return keys. It omits only minor details such as error behavior or units for topup_usd, which are inferable from the key names.

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?

There are zero parameters, so there is nothing for the description to add beyond the schema. The baseline for a parameterless tool is 4, and the description does not introduce any parameter confusion.

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 identifies the resource (account options) and the data returned (purchases_enabled, topup_usd, free_tier_calls, billing_url, checkout_path). The opening phrasing is a grammatical fragment rather than an explicit verb, which costs a point, but the return list makes the operation clear. It is distinguishable from siblings like account_usage and start_checkout.

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 explicitly states when to use it: 'Call this (or read a 402 body) before start_checkout.' It also flags that the endpoint is unauthenticated, which tells the agent no auth setup is needed, and offers a concrete alternative path (reading a 402 body).

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