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

With no annotations, the description carries the full burden and does reasonably well: it discloses the required staff/account session, the defaulting behavior of the month argument, the exact metric set returned, and the caveat that rates are proposals with no payment collected. It omits pagination/result-size behavior, but the shape of the operation is clear.

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 but well-ordered sentence-front-loaded with the access constraint, then scope, then metrics, then the billing caveat. Nothing is wasted, though the '(docs/11)' reference and the phrasing are slightly cryptic.

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?

No output schema exists, and the description compensates by enumerating the returned metrics and totals. No annotations exist, and it supplies the auth/session requirement and the no-payment caveat. Only pagination and exact response structure are unaddressed, which is a minor gap for a monthly aggregate reporter.

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 coverage is 0% and the schema only supplies a YYYY-MM pattern, so the description must compensate. It does: it names the parameter's purpose, its YYYY-MM format, and the 'default this month' behavior the schema omits. The single parameter is effectively fully documented.

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 specific resource (monthly usage per workspace) and enumerates the metrics returned: calls, connected minutes, charges, credits, net, plus platform totals. The 'Platform staff only' qualifier distinguishes it from the tenant-facing usage_get, though no sibling is named explicitly.

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?

'Platform staff only (account session)' sets a clear access precondition, which is useful gating context. However, it never says when to choose this over platform_overview, platform_calls_list, or usage_get, and gives no exclusion criteria, leaving the choice to inference.

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