billing

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

With no annotations, the description carries the full burden and largely meets it: it discloses that beta usage is free, that topup returns a Stripe URL the agent must show to the user, and that renders are charged by GPU second only for frames that actually rendered. It does not cover auth requirements, failure modes, or whether topup charges immediately versus at checkout completion.

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 purpose is front-loaded in the first clause, and each subsequent sentence adds a distinct fact (beta behavior, paid branches, charging model). It is dense and slightly long for a one-parameter tool, but no sentence is redundant.

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?

An output schema exists, so return-value detail is not strictly required, yet the description helpfully summarizes what each mode returns. Given the financial nature of the tool, the main residual gap is the absence of any note on permissions or error handling, but nothing essential for correct invocation 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 description coverage is 0% and the single parameter is undocumented in the schema, yet the description fully compensates: topup_yen = 0 triggers payment confirmation and balance readout, while topup_yen > 0 with a minimum of 500 triggers a Stripe checkout URL. An agent can choose a value correctly without any other source.

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 opens with a concrete verb and resource: 'Check the account's quota or credit', and then details the mode-dependent payload (usage/quota/reset in beta, balance/price/previews when paid). This is clearly distinct from the render_* and scene_info siblings, which do not touch account balances or payments.

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 gives explicit conditional guidance keyed on topup_yen: 0 to confirm a just-made payment and read the balance, >0 (min 500) to obtain a checkout URL. It also frames the beta-vs-paid distinction. What's missing is routing advice against any alternative tool, but for this resource there is no competing sibling to name.

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