get_usage

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

Since no annotations are provided, the description carries the full burden. It mentions the HTTP GET method and 'current API key', which imply read-only behavior and authentication context. However, it does not disclose potential quirks like error handling or whether the month format is strictly validated, though the output schema may cover return values.

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, front-loaded sentence that includes the purpose, endpoint, and parameter format without any wasted words. It is highly concise and well-structured.

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 one-parameter read tool with an output schema present, the description adequately covers what the tool does and how to specify the month. It lacks usage guidelines, but the tool's simplicity and the presence of an output schema reduce the need for extensive additional context.

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 schema has zero description coverage, so the description's note that month is optional with a YYYY-MM format adds critical meaning beyond the raw schema, which only indicates string|null with a default of null. This gives the agent enough to construct a valid call.

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 the tool returns usage for the current API key, with a specific verb and resource, and references the endpoint (GET /v1/usage). It is distinct from siblings like get_limits, which concerns limits rather than usage.

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?

No guidance is provided on when to use this tool versus alternatives such as get_limits. There are no exclusions or context about typical usage scenarios, leaving the agent to infer 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.