Verify many Japanese companies

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

Goes well beyond the readOnly/openWorld/non-destructive annotations: it discloses per-tier batch limits, billing behavior ('malformed or mistyped numbers... are not charged; each well-formed number is one metered lookup'), an output-size warning, and the data provenance. These are the operational facts an agent needs before committing to a batch.

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?

Purpose and the sibling relationship are front-loaded in the first clause, followed by limits, billing, and output caveats in descending priority. Dense but every clause carries actionable information; nothing is padding.

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?

With no output schema, the description compensates by describing the `invalid` bucket, the metered-per-number cost model, and the large-output caveat. It does not describe the result shape for well-formed numbers, which is the one remaining gap for a batch verification call.

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% and the single parameter already documents accepted identifier formats, so the schema carries the parameter burden. The description adds only the downstream behavior of malformed entries (returned under `invalid`), not input syntax or format 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?

States a specific verb and resource and explicitly frames itself as the batch form of a named sibling ('The same check as verify_japanese_company for many numbers in one call'). An agent can distinguish it from the single-lookup sibling without opening either schema.

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?

Names the sibling it parallels and the condition that selects it (many numbers in one call), plus per-tier batch caps that tell the caller whether a batch will fit. It never states the inverse routing rule (use verify_japanese_company for a single number), so it stops short of full when/when-not guidance.

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