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

Annotations already provide idempotency and destructive-safety; the description adds valuable behavioral detail: determinism, citation of primary sources, exact NTA table, and a 'never billed for errors' policy. It does not contradict annotations, and the added payment/billing context goes beyond the structured fields.

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 compact and front-loaded with the core function, followed by the exact-table claim and pricing/accuracy guarantee. Every sentence adds distinct information with no filler.

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?

The tool has 8 parameters and no output schema, yet the description plus full schema coverage makes its purpose, scope, and result type clear. The lack of an explicit return-format description is a minor gap, but the description's determinism, pricing, and source-citation details make it sufficiently complete for correct invocation.

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?

Input schema covers 100% of parameters, so the baseline is 3 and the description need not restate them. It adds broad meaning (gross salary and the tax components) but supplies no param-level detail beyond the schema.

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 clear transformation ('annual gross salary to net take-home') and names the exact components (social insurance + income tax + resident tax), which distinguishes it from siblings like jp_bonus_net and jp_payroll_suite. The 'Exact NTA Beppyo-5 table' further anchors its specific scope.

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 use for annual salary-to-net calculations but gives no explicit when-to-use guidance or exclusions. It never names alternatives such as jp_bonus_net for bonus-only calculations or jp_payroll_suite for broader payroll needs.

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