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

With no annotations, the description carries the full behavioral burden. It usefully discloses that the tool returns payment requirements, including exact amount and address, and that balance payment is immediate, but it omits important traits such as whether the order reserves the domain, how long it remains valid, auth requirements, and idempotency behavior.

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 short sentences and front-loads the core action. It is efficient, though it could put the payment-return behavior and balance shortcut into clearer relation to the order lifecycle.

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?

This is an 8-parameter payment/order tool with no annotations, no output schema, and low schema description coverage. The description explains only the basic return shape and one payment enum value; it does not cover the order lifecycle, idempotency, nameservers, years, or how this step relates to check_order and pay_order.

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 only 38%, so the description needs to compensate for undocumented parameters such as domain, years, pay_with, nameservers, and idempotency_key. It only clarifies the balance value of pay_with, leaving most parameters without added meaning beyond the schema.

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 verb and resource: 'Create a registration order.' That is clear enough to act on, but it does not explicitly distinguish this tool from close siblings such as create_cart, pay_order, or buy_with_balance.

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 mention that 'pay_with=balance pays instantly from prepaid balance' implies one usage path, but the description does not say when to use this tool versus create_cart, pay_order, or buy_with_balance. There are no exclusions or prerequisites.

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