Consumption tax for one rate on one invoice

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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds genuinely useful behavioral detail beyond that: the exact exclusive vs inclusive formulas and the default rounding mode of floor. It stops short of stating what the response contains.

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?

Three dense clauses, front-loaded with the core formula and then the branch conditions and default. No filler, no repetition of schema enums verbatim, and the default is called out inline.

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?

There is no output schema, so the description must define the return value, and it only implies that the tax figure is returned without saying whether the tax-inclusive total is also included or what type/units to expect. For a pure calculator with no output schema, that leaves a real gap.

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?

With 0% schema description coverage, the description carries the full burden and mostly does: it explains how rate is applied, what price_basis exclusive/inclusive mean mathematically, and that rounding defaults to floor. Only amount ('total') and the meaning of the 10 vs 8 enum values are left implicit.

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 concrete computation ('Tax = round(total x rate) once for the whole invoice') for a specific resource, Japanese consumption tax on a single invoice. It is clearly distinguishable from jp_invoice_check and jp_invoice_registration_number, though it never names a verb like 'compute' or 'calculate' explicitly.

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?

Usage is only implied: the title's 'one rate on one invoice' hints that multi-rate invoices need multiple calls, but the description never says when to use this versus the sibling tools or what the prerequisites are. An agent can infer the context but gets no explicit routing guidance.

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