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

The annotations already establish this as a safe, read-only, closed-world operation, so the description is not responsible for the safety profile. It does add real value by enumerating the returned dimensions (limit vs used, over-limit status, included/used/remaining/hard-stop credits), which no output schema provides. It omits freshness/lag and whether the figures are point-in-time or period-scoped.

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 sentence, front-loaded with the subject (usage against plan) and with two compact parenthetical enumerations that each carry distinct information. No filler, no repetition of the name or annotations.

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 parameters and no output schema, the description is the only carrier of return-value meaning, and it does that job well by listing the fields an agent can expect. It is nearly complete; the only gap is not stating the reporting period/currency/units for the credit figures.

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?

Zero parameters, which sets the baseline at 4 per the rubric; there is nothing for the description to disambiguate. The description appropriately spends its words on output content instead of inventing 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 description precisely enumerates the resource returned: record and seat limits (used/max, over-limit flag) plus this month's AI credit breakdown by feature. That is a concrete, verifiable statement of scope rather than a restatement of the name. It stops short of a 5 because it does not differentiate itself from the overlapping sibling ai_usage_summary, which an agent may reasonably confuse with the AI-credits portion.

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?

Usage is only implied: an agent can infer it should call this when it needs plan/seat/credit consumption figures, but no when-to-use condition, prerequisite, or preferred alternative (e.g. ai_usage_summary vs workspace_activity) is stated. Nothing misleading, but nothing explicit either.

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