Check API usage

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, covering safety and idempotency. The description adds that it does not consume quota, which is a valuable behavioral detail beyond the annotations. However, it doesn't describe the exact format of the response (e.g., whether it's JSON, field names), relying on the output schema, which is not provided.

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 two concise sentences that front-load the key information (what it reports and that it's free), then adds usage guidance. No wasted words, every sentence earns its place.

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 tool with strong annotations, the description is nearly complete. It explains the return content and the non-consuming nature. The only minor gap is the lack of an explicit mention of the response format, but since there's no output schema and the tool is simple, this is a small omission.

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 description correctly focuses on what the tool returns and its side effects. With no parameters to describe, the description fully covers the input semantics, making it complete.

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 reports the calling API key's monthly quota details (tier, limit, usage, reset), which is specific and distinct from siblings like get_financials or list_filings. It uses a clear verb ('report') and resource ('calling API key's current monthly quota'), making it unambiguous.

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 explicitly says it is free to call and does not consume quota, and it recommends checking it before large batches to avoid rate limits. This provides clear context for when to use it, though it doesn't mention alternatives—but given this is a unique monitoring tool, that's acceptable.

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