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

Annotations already declare readOnlyHint and closed-world scope, so the safety profile is covered. The description goes beyond them by naming the auth requirement and, importantly, enumerating what comes back (app, site-vs-all-sites license, provenance free/order/grant, update end date) — valuable since no output schema exists. It stops short of saying how results are ordered or whether they can be truncated.

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 tight sentence with the subject front-loaded and no filler. The field list is dense but slightly cryptic in places — 'license (site or all sites)' reads as shorthand an agent must decode.

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 no-parameter read tool with annotations covering safety, the description supplies the missing pieces: what is listed, what fields appear, and the sign-in requirement. Only minor gaps remain, such as result volume or whether the list is paginated.

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 tool takes zero parameters, so there is nothing for the description to disambiguate and the schema baseline applies. The parenthetical distinctions like 'site or all sites' describe returned data rather than inputs, which is useful but belongs to output transparency, not parameter semantics.

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 phrase 'The apps this account owns' plus the enumerated payload fields makes it clear this is a listing of the account's owned apps and their license/provenance/expiry state. It is distinguishable from singular siblings like get_app, get_license, and get_download, though it never explicitly contrasts itself with list_sites or list_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?

The only guidance is the precondition 'Needs the owner signed in,' which tells the agent about authentication but not when to reach for this over get_app/get_license. Usage is implied by the scope word 'owns' rather than stated as a selection rule.

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