Check a Japanese qualified invoice (適格請求書)

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

Beyond the read-only, idempotent, non-destructive annotations, the description discloses the offline limitation, the specific rounding behavior it enforces, the common mistake it catches, and the structure of returned errors, warnings, required items, and per-rate expected tax. This is substantial behavioral context that annotations alone do not provide.

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 front-loaded with the core check and then systematically covers required items, rounding, input shape, returns, and the offline limitation. It is dense and useful, though the final Japanese sentence largely repeats the opening purpose and the long parenthetical item list is heavy, so it is not maximally concise.

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 complex validation tool with no output schema and a nested input object, the description supplies both the domain rules and the return-value structure. It clarifies the offline scope, the six required items, rounding behavior, and output fields, leaving no major operational gap for an agent to call it correctly.

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?

Although the schema reports 100% description coverage, the top-level schema only describes the invoice object as 'as described above.' The real parameter semantics live in the description, which defines issuer fields, date, buyer, price_basis enum values, items with rate and reduced flag, totals by rate, and optional rounding options. This is essential and adds meaning well 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 specific verb and resource: checking a Japanese qualified invoice against six required NTA items and the per-rate rounding rule. It explicitly distinguishes itself from registration verification by noting it is offline and does not check whether the registration number is currently valid, which separates it from the jp_invoice_registration_number sibling.

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?

It gives clear context for when to use the tool: validating qualified invoice fields and catching the per-line versus per-invoice rounding error. It also clarifies an important exclusion by saying it does not verify current registration status, implicitly routing that need elsewhere. It does not explicitly compare against jp_invoice_tax, so it falls short of full alternative guidance.

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