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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=false, and destructiveHint=false, so the safety profile is covered. The description adds only the 'Works on: Demo shop (sample data)' environment note and no further behavioral context (no pagination, no return format), which is minimal value beyond the annotations.

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 '[Orders]' prefix front-loads the domain, but the body sentence is somewhat garbled, conflating 'courier accounts' with 'courier codes the marketplace knows and who pays for each'. It is short, but the muddled phrasing costs it efficiency.

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?

For a simple, single-optional-parameter, read-only list tool with an output schema and full annotation coverage, the description is largely sufficient. The only missing element is usage routing against siblings, which is minor for a straightforward list operation.

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% and the single 'account' parameter is fully documented in the schema, including its optionality. The description adds no parameter meaning beyond what the schema provides, so the baseline of 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 clear verb+resource: it lists the courier accounts configured on the seller account, tagged [Orders]. The second clause ('or the courier codes the marketplace knows and who pays for each') muddies the scope somewhat, and no sibling tool is named for differentiation, but the core purpose is discernible.

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 offers no when-to-use guidance or alternatives among the many sibling list tools (list_accounts, orders_list, invoices_list, etc.). It only notes 'Works on: Demo shop (sample data)', which is an environment constraint, not usage routing.

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