get_usage

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It clearly states the returned data (used, limit, remaining, reset date) but does not explicitly mention that the operation is read-only, nor does it address potential side effects, error conditions, or authentication requirements. The behavior is adequately implied for a simple get, but not fully elaborated.

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?

The description is a single, well-structured sentence that leads with the action and resource, then immediately lists the returned fields. There is no wasted wording, and the most important information is front-loaded. It is exemplary in conciseness.

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?

For a simple no-parameter read operation, the description is fairly complete: it specifies the plan, usage, quota, and reset date. However, it does not differentiate from the similar sibling get_quota, and since there is no output schema, the agent relies entirely on the description for return structure. The listed fields are helpful, but a brief note on when to prefer this over get_quota would enhance completeness.

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 has zero parameters, so the schema is trivially covered. Since there are no parameters to document, the description does not need to add parameter-specific details. Per the baseline for zero-parameter tools, a score of 4 is appropriate because the description adequately conveys the tool's purpose without needing to explain 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 clearly states a specific action ('Get') on a specific resource ('this API key's plan and current-month usage') and enumerates the exact fields returned (used, limit, remaining, reset date). This is unambiguous and distinct enough to convey the tool's core function, even though it does not explicitly contrast with siblings like get_quota.

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 description provides no guidance on when to use this tool versus its siblings, particularly get_quota or get_key_status. It simply states what it does without any context about scenarios, prerequisites, or exclusions. An agent would have to infer when this is the appropriate choice from the name and description alone.

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