get_usage

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

No annotations exist, so the description carries the full disclosure burden. It does useful work by spelling out the returned fields in the absence of an output schema, and 'Get' plus 'summary' implies a non-mutating read. It says nothing about auth/permission requirements, rate limits, or whether the period is calendar-month or billing-cycle based, all of which matter for a quota-style tool.

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 front-loaded sentence with no filler; every clause contributes either the resource or one of the returned values. Nothing is repeated from structured fields and nothing is wasted.

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 compensates well by listing the four values returned, which is exactly what an agent needs to decide this tool answers a usage question. The remaining gap is sibling disambiguation against get_usage_hourly/history/by_feed within a large, similarly named cluster.

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 and the schema is an empty object, so there is no parameter semantics to explain; the baseline of 4 applies. Nothing in the description misleads about inputs.

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?

Specific verb ('Get') plus a well-defined resource ('delivery usage summary for the current period'), and it enumerates exactly what the summary contains: totals, failures, tier, and remaining monthly bucket. It does not, however, distinguish itself from close siblings like get_usage_by_feed, get_usage_hourly, or get_usage_history, so the agent must infer that this is the aggregate/current-period variant.

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 phrase 'for the current period' implicitly signals this is the rolled-up current snapshot rather than a historical or per-feed breakdown, which nudges the agent away from get_usage_history and get_usage_by_feed. But no sibling is named and no condition for choosing among them is stated explicitly, leaving routing to inference.

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