List invoices

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

Annotations already grant read-only, idempotent, non-destructive status, so the description adds the genuinely non-obvious parts: newest-first ordering, the default date window, and the 'BookingKoala gives no total: next_cursor is set while a full page comes back' pagination quirk. That last clause is exactly the kind of behavior an agent would otherwise get wrong.

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?

Front-loaded with the one-line purpose, then a dense second paragraph covering return fields, filters and pagination. Nearly every clause earns its place, though the 'BookingKoala gives no total' phrasing is slightly opaque and the field list packs a lot into one sentence.

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 by enumerating the fields returned (number, customer, type, status, total, paid, amount due, dates). Combined with ordering, pagination and routing hints, an agent has enough to call it and to read the result, though edge cases like empty results go unstated.

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 schema already documents limit, cursor, dates, pay_status enum, customer_id and search. The description restates the default date window and search fields but adds no syntax or format detail beyond the schema, so baseline 3 applies.

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?

Opens with a specific verb+resource and scope: invoices for the whole store or a single customer, with payment status, totals and amount due. That scope statement alone lets an agent separate it from list_charges and list_drafts without opening a schema.

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?

Spells out the three filter axes (customer, payment status, issue date range), the free-text search targets, and the default two-year-back/one-year-ahead window, which is real usage guidance. It also routes the invoice_id it returns to resend_invoice. It stops short of naming when a sibling like list_charges is the better call.

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