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

Annotations already declare readOnly, idempotent, and non-destructive, so safety is covered. The description adds genuinely useful context beyond that: results are limited to this account's orders, and it discloses the return contents (payment state options including 'on account' with invoice, and links to certified translation files once delivery occurs). It does not cover failure behavior for an unknown or foreign order number.

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?

A single dense sentence that front-loads the resource and then the returned fields. Nothing is wasted, though the parenthetical payment enumeration makes it list-heavy rather than crisp.

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 describes what the call returns, including payment semantics and delivery-file links, and notes account scoping. It leaves undefined what happens for an invalid or non-owned order number, which is the main remaining gap for a single-parameter 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?

With one parameter at 100% schema description coverage, the schema already documents order_number fully, including the example '43392' and range bounds. The description adds nothing beyond the schema, so the 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?

The description names a specific resource (one of this account's orders) and enumerates what status comprises: progress, expected delivery, payment state, and delivery-file links. It does not explicitly contrast with the sibling list_my_orders, so a reader must infer the singular-vs-list distinction from 'one of this account's orders'.

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?

There is no explicit when-to-use statement, no prerequisites, and no mention of the obvious alternative (list_my_orders) or how to obtain a valid order number. Usage is only implied by the required order_number and the account-scoping phrase.

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