List invoices

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

There are no annotations, so the description carries the full responsibility for behavioral disclosure. It does convey that this is a read-only listing action and details the output fields including the computed 'balance still due after any credit note.' However, it omits operational behavior such as pagination, ordering, default range when no filters are given, and whether results are limited. This is acceptable but not thorough.

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 split into two informative sentences: one for the returned fields and one for the filter usage. It front-loads the core purpose and contains no filler or obvious redundancy. The phrase 'by number' is slightly confusing but the overall structure is still efficient and scannable.

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 the low complexity (four optional, simple parameters; no nested objects; no output schema), the description covers the returned fields and filter combinations well enough for an agent to form a basic call. It does not mention pagination, sorting, or defaults, but for a straightforward list tool these omissions are not fatal. The description compensates for the absence of an output schema by documenting the response fields.

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?

The description acknowledges the three filter dimensions (status, client, date range) in a way that maps to the schema parameters, adding some context beyond parameter names. Yet it does not clarify the `client` format or the meaning of the `status` values beyond what the schema enum already shows, and the phrase 'List invoices by number' confusingly suggests a filter that does not exist among the parameters.

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 clearly states 'List invoices' as the verb and resource, and enumerates the returned fields (client, dates, currency, subtotal, discount, tax lines, total, status, paid, credited, balance). It does not explicitly distinguish this from sibling tools like invoice_get or invoice_pdf, so it falls short of a full 5, but the purpose is not ambiguous.

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 gives clear context for basic usage: list invoices and filter by status, client, and date range. However, it does not explain when to prefer this tool over alternatives such as invoice_get, invoice_pdf, or overdue_report, nor does it provide any exclusion criteria. The intended usage is implied rather than fully spelled out.

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