list_member_usage

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

Annotations already declare readOnly, idempotent, closed-world and non-destructive, so the safety profile is covered. The description adds two pieces of context beyond that: the required `billing:read` scope and the fact that results are bounded to the current billing period, both of which materially affect a call.

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?

Two short sentences with nothing wasted, and the scope requirement is called out separately so it is easy to check. It is slightly under-specified rather than bloated; a verb-led opening would have made it sharper.

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 source of information about the result, and it never says what metrics per member are included (calls, minutes, cost) or whether historical periods are reachable. That is a meaningful gap for a reporting endpoint, though the core intent is legible.

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 no parameters, so there is nothing the description could clarify; the baseline for zero-param tools applies. The 'current period' phrasing does implicitly confirm there is no date-range parameter.

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 names the resource and scope (per-member usage, current period), so an agent can roughly infer the output. However, it is a noun phrase with no verb and gives no hint how it differs from lookalike siblings such as get_usage or get_analytics_by_member.

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 call this versus get_usage, get_analytics_by_member, or get_billing_status. The only usage signal is the scope requirement, which is an access precondition rather than a routing rule.

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