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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is covered. The description adds meaningful behavioral detail by explaining that tax figures combine platform-reported order tax with computed manual TaxRule entries where the platform reported none or a fixed-amount rule applies. This clarifies the underlying calculation behavior 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 three sentences with no filler. The primary output is front-loaded, the second sentence explains a nuanced data-combination behavior, and the third sentence gives a useful dashboard comparison. 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?

Given the tool has one optional parameter, a rich output schema, and safety annotations, the description is largely complete: it states the result components, the data sources, and the calculation nuance. The only gap is the absence of explicit alternative-tool routing, but that is already accounted for under usage guidelines.

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?

Schema description coverage is 100% for the single 'days' parameter, including its bounds and default value. The description only mentions a 'trailing N-day window' and does not add extra parameter-level semantics, so it neither compensates for missing schema documentation nor adds meaningful value beyond it.

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 opens with a specific verb and resource: 'Get period tax totals and the blended effective tax rate over a trailing N-day window, plus a per-country split.' This clearly distinguishes it from sibling reporting tools by naming tax-specific outputs and the country breakdown, so an agent can recognize its purpose without ambiguity.

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 implies the tool is for tax-period summaries by noting it 'Mirrors the dashboard tax settings page tiles,' but it does not explicitly state when to use this tool over alternatives or when not to use it. No sibling alternative is named, so the usage guidance is only implied rather than explicit.

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