Get API usage

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

Annotations already establish readOnlyHint=true and openWorldHint=false, so the safety profile is partly covered. The description adds genuinely new behavioral context: the counters are cumulative 'since it started' (explaining the non-idempotent, changing return values) and the call is free ('Uses no credits'), which the annotations do not convey.

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 sentences, front-loaded with the core purpose, followed by a short cost note. The longer first sentence is a necessary field enumeration because no output schema exists, so 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 output schema, the description correctly carries the burden of describing the return values and does so field by field, plus notes cost and limit semantics. Minor gaps remain (e.g., response format, whether counts are server-wide or per-key, when limits reset), but nothing essential for invocation is missing.

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, so there is nothing for the description to disambiguate; the schema and description are consistent. Baseline 4 applies for a parameterless tool.

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?

States a specific verb (Shows) and resource (this server's API usage), then enumerates exactly what is reported: call counts, cache hits, credits spent, and remaining per-minute/per-day limits. This clearly separates it from the sibling tools, all of which fetch external travel/currency data rather than server telemetry.

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 this is for checking quota/credit consumption before or after making calls, and 'Uses no credits' hints it is safe to poll. However, the description names no trigger condition and no alternative, so the when-to-use is left to inference.

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