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

Annotations already declare readOnlyHint=false, idempotentHint=true and destructiveHint=false. The description adds meaningful context beyond them: 'This tool moves no money' clarifies that no financial side effect occurs, and the auth prerequisites are spelled out. It does not describe the returned page/URL format, so it stops short of full disclosure.

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?

Three short sentences, front-loaded with the core action and immediately followed by the key caveat ('moves no money') and the auth conditions. No filler, though the auth sentence is slightly dense.

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?

With no output schema, the description carries the return-value burden and does so at a high level ('returns a page'). Auth conditions and the no-money guarantee are covered, but the absence of any mention of the sibling list-payment-link tool leaves the routing decision partly to inference.

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 100%, so the baseline is 3. The description goes slightly beyond the schema by tying trial_code to the requirement that it carries the user's e-mail address and by framing the three mutually exclusive auth paths, which helps the agent decide whether to pass trial_code at all.

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?

States a specific verb and resource: it returns a payment page where the user buys Wozapi credits for single lookups via iDEAL. An agent can tell this is a credit top-up link rather than a general payment link, though the sibling create_list_payment_link is never named to sharpen the distinction.

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 lists the valid authentication contexts (signed in, connected API key, or a trial_code tied to the user's e-mail), which is real usage context. It does not, however, state when to prefer this tool over create_list_payment_link or what to do when none of those auth conditions hold, so selection guidance is only implied.

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