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

Annotations already cover the read-only/non-destructive safety profile, so the description earns credit for adding real behavior: default sort order ('Ordered by due date, latest first'), the null-means-unpaid semantics of completed_at, and the honest caveat that amount units are undocumented (normally smallest currency unit). Pagination behavior is left to the schema's limit/offset/next_offset descriptions.

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?

One dense but front-loaded sentence: purpose first, then return fields, then filtering, then ordering, then endpoint. The parenthetical field inventory is long but each item carries information an agent would otherwise have to guess.

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 usefully enumerates the returned fields and their null semantics, and it covers sorting. Eight params are all schema-documented, so the only remaining gap is pagination and any guidance on when this list should replace a booking-level lookup.

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 every filter (booking_id, invoice_id, due_from/due_to, completed, offline) is already documented in the schema. The description restates the filter axes at a high level without adding syntax, defaults, or combination rules beyond what the schema provides; 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?

States a specific verb and resource ('List payments') and enumerates the payment subtypes (deposits, balances, offline) plus the endpoint, which distinguishes it from list_invoices. It never explicitly contrasts itself with the closest sibling, bookingmood_list_invoices, so it falls short of a 5.

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 sentence 'Filter to unpaid payments, a booking or a due date' implies the intended retrieval scenarios but never states when to choose this over list_invoices or get_booking. Usage is inferable from the filter list rather than spelled out.

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