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

readOnlyHint=true already establishes the safety profile, so the description needn't repeat it. What it omits is everything else behavioral: whether results are scoped to the authenticated agent, whether the list is complete or paginated, and whether it includes shipping/status info. With annotations covering only read-only-ness, this detail is missing.

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?

Three words is certainly concise, but here brevity crosses into under-specification rather than economy — there is no front-loaded directive, and nothing is stated about return content or scoping. It is short but not information-dense.

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 and no annotations beyond read-only, the description must convey what comes back and how the list is scoped or paginated; it conveys none of that. For a listing tool where result shape and boundaries matter, this is a substantial gap.

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 single optional api_key parameter has full schema description coverage explaining the iam_ format and the fallback for clients without an Authorization header, so the schema carries the burden completely. The tool description adds nothing about it, which is acceptable at 100% coverage but earns no bonus.

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?

"Everything you bought" implies a list of the caller's own purchases and implicitly contrasts with the sold-side sibling get_sales, but no verb or resource is stated explicitly and the scope (all time? paginated?) is unknown. An agent can guess the purpose but cannot confidently distinguish it from get_order or get_sales without inference.

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 statement of when to use this tool, no prerequisites, and no alternative named among siblings such as get_order (single purchase) or get_sales (items sold). The only guidance is the faint bought-vs-sold implication in the wording.

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