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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds genuinely new behavioral context beyond annotations: the required key scope (sites:read) and the fact that 'hold' means public pages are stopped, which is not derivable from structured fields. It stops short of noting rate limits or staleness of the numbers.

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?

One dense sentence with the resource and scope front-loaded followed by the enumerated return dimensions; every clause carries information. It is long but not padded, though the trailing metric list could be tightened.

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 carries the burden of explaining return values and does so by listing each metric and the hold flag; the auth scope is also stated. What remains unclear is only whether the data is near-real-time versus cached, which is a minor gap for a read-only reporting tool.

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?

There is a single parameter with 100% schema coverage, where the schema already explains that 'site' is the ID from list_sites with an example. The description adds only the indirect hint that the scope is site-level ('sites:read') and no format or acquisition detail beyond the schema, 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?

The description gives a specific verb and resource ('Read the site's usage against its plan') and enumerates the exact dimensions returned (forms, cms, storage, ai, requests with limits, period, hold flag). An agent knows precisely what comes back. It does not name the closely related sibling get_usage_pv, so the differentiation is only partial.

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?

'as the admin's usage panel shows it' implies the use case (checking plan consumption), and the sites:read scope hints at access prerequisites. However, it never says when to prefer this over the sibling get_usage_pv, nor states any exclusions or conditions.

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