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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds a minor behavioral nuance by saying 'Poll', which implies the status can be checked repeatedly and may change, but it does not mention external latency or error 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 one front-loaded sentence with no filler. Every phrase adds meaning, and it avoids repeating the title or schema.

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?

Given one required parameter, an output schema, and read-only annotations, the description is nearly complete for invocation. The only real gap is not addressing when in the payment flow this should be used, which is more of a usage-guidance issue.

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%, so the description must compensate. It does convey the key semantic: paymentId is a NOWPayments id. For a single string parameter, this is sufficient to call the tool correctly, even though the description does not explicitly name the parameter.

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 ('Poll'), a specific resource ('invoice / payment status'), and the identifying namespace ('NOWPayments id'). This clearly distinguishes it from payment creation or Stripe verification tools in the sibling list.

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 explicit when-to-use guidance or alternatives are mentioned. The verb 'Poll' implies repeated status checks after a NOWPayments payment is created, but the choice against sibling tools like ucode_payments_stripe_verify is left to inference.

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