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

readOnlyHint=true already declares this a safe read, so the bar is lower. The description usefully adds that refunds appear as negative amounts, but says nothing about ordering, pagination behavior in practice, or what a payment record contains (no output schema exists to cover this).

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?

Two tight sentences, front-loaded with what is returned, followed by the underlying endpoint mapping. No filler; the endpoint reference grounds the call semantics rather than padding.

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 a low-complexity read-only list with one required parameter and full schema coverage, so little burden remains. Scope, the refund convention, and the endpoint are stated; only the shape of individual payment records is left implicit, which is acceptable given the simplicity.

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 100% (pageNumber, itemsPerPage, pageNavigationToken, bookingNumber all documented in the schema), so the baseline is 3. The description adds no parameter-level meaning beyond what the schema already says.

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 (List) and resource (payments/refunds) scoped to 'one booking', which cleanly separates it from the sibling bookeo_list_payments (all payments). The negative-amount convention for refunds is a concrete detail that further pins down what is returned.

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 phrase 'for one booking' implies you must already have a bookingNumber and want its payment history, but there is no explicit when-to-use guidance, no mention of the alternative bookeo_list_payments or bookeo_get_payment, and no stated prerequisites. Usage 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.