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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so the safety profile is covered. The description adds useful behavioral context beyond that: dates are epoch milliseconds, purchaser names and emails are returned, and it names the underlying API path. It does not discuss rate limits or pagination behavior beyond what the schema states.

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 compact sentences plus a short API line; the returned-field list and filtering capability are front-loaded with no filler. Slightly dense in its field enumeration, but every element carries information.

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?

There is no output schema, and the description compensates by describing the returned fields and that purchaser names and emails come back. Combined with complete parameter documentation and read-only annotations, an agent has what it needs; only minor gaps like sorting/pagination caveats remain, and those live in the schema.

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%, so limit/offset/order/fields/filters are already fully documented, which sets the baseline at 3. The description reinforces the status filter with an example ('Overdue') and clarifies date values are epoch milliseconds, but adds little else the schema doesn't already say.

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 the organization's finance invoices') and enumerates the data it covers (number, currency, totals, purchaser, voided flag, dates), plus the backing endpoint POST /finance/invoice/list. It does not explicitly differentiate from siblings, but no other invoice tool exists in the sibling set, so an agent can place it unambiguously.

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?

Says it can be filtered 'by status (e.g. Overdue) or any property', which implies how to narrow results, but gives no when-to-use/when-not guidance and no exclusions. With no competing invoice-listing tool the implied usage is adequate but thin.

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