bunny_get_billing_summary

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so no safety contradiction exists. The description adds value by specifying exactly what data is returned, including current balance and per-service breakdown, which is useful behavioral context beyond the annotations.

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 immediately states the action and resource, followed by concise examples of the returned content. There is no filler or redundant wording.

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 billing summary tool, the description fully covers what the agent needs to know: what the tool does and what data it returns. No output schema exists, but the listed summary components provide sufficient 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 coverage is 100%, so the schema imposes no burden and the description does not need to explain parameters. The baseline of 4 applies 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 states a specific verb ('Retrieve'), a clear resource ('billing summary for the account'), and enumerates the key contents: current balance, this month's charges, and per-service usage breakdown. It is unambiguous and distinguishes this tool from the many get_* siblings by focusing on billing-specific data.

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 intended use clear: any time an agent needs account-level billing information rather than generic statistics or account details. It does not explicitly name alternatives or exclusions, but the billing-specific scope gives sufficient context among siblings.

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