api_usage

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

The annotations already declare readOnlyHint=true and openWorldHint=true, so the description does not need to restate that this is a safe read operation. The description adds that the tool reports rate limits and usage counts, which is useful context. It does not disclose details like reset timing or units, but for a zero-parameter read-only tool this is acceptable.

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 states exactly what the tool does. Every word earns its place, and there is no redundant or filler content. It is appropriately sized for the simplicity of the tool.

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 zero-parameter, read-only status tool, the description adequately conveys what the agent will get: rate limits and usage counts. There is no output schema, so the description carries the burden of describing return content, and it does so. It could mention units or reset period, but the current level is sufficient for correct invocation and expectation-setting.

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 and schema description coverage is 100%, so there are no parameter semantics to clarify. Per the baseline for zero-parameter tools, the description does not need to compensate for any parameter documentation gaps. Nothing more is needed here.

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 uses a specific verb ('Show') and names the exact resource: API rate limits and call usage. This clearly distinguishes it from the sibling tools, which are all about simulations, storage, or file operations. An agent can immediately tell what this tool does without needing to inspect anything else.

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 makes the usage context clear: call this tool when you need to know API rate limits or consumed quota. There are no competing alternatives among the siblings for this kind of information, so explicit when-not-to-use guidance is unnecessary. It provides clear context without exclusions.

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