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

Annotations only declare readOnlyHint and openWorldHint, so the safety profile is covered; the description goes further by disclosing result semantics and limits: per-registry status/version date/source, 'what was not checked', that a domain alone stays unverified, that no match is not proof of non-existence, and that no compliance determination is made. It does not mention auth requirements or rate limits, so it is strong but not exhaustive.

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?

Front-loaded with the multi-registry scope, then alternatives, then caveats; every clause carries information and there is no filler. It is a dense single block rather than structured bullets, which slightly hurts scanability for a 10-parameter tool.

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 an output schema present, the description need not explain return values, yet it still clarifies scope, coverage limits, negative-result meaning and the no-compliance-determination stance. Combined with annotations covering read-only/open-world behavior and 100% schema coverage, an agent has everything needed 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?

Schema description coverage is 100% and each of the 10 parameters already carries its own description with examples (name, domain, prefecture, edinet_code, address_hint, corporate_number, registration_numbers). The description adds almost no parameter-level detail beyond the schema's own 'never resolved to an organization' / 'unverified' notes, so baseline 3 applies.

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+resource: a public-record check that spans several named Japanese registries (FSA, MOF, EDINET, ISA, gBizINFO) at once. It explicitly distinguishes itself from the single-registry tools (jp-finance, jp-sanctions, jp-edinet, jp-ssw-support-orgs), so an agent can route without opening a 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?

Gives an explicit when-to-use condition ('checks spanning several Japanese registries at once') and an explicit when-not with named alternatives ('For one registry, use jp-finance, jp-sanctions, jp-edinet or jp-ssw-support-orgs'). Nothing about routing is left to inference.

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