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

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint, so the safety profile is covered. The description adds the useful claims that checks are deterministic and that this is a single-call/'one receipt' operation, but 'explicit scope' is never explained and no cost, coverage limits, or failure behavior are described.

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?

It is short and front-loaded, which is good, but the opening 'One call, one receipt' is slogan rather than information, and the space saved is spent on unexplained phrases like 'explicit scope' instead of usage context.

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?

An output schema exists, so return values need not be described, and annotations cover the safety profile. For a two-optional-parameter read-only check, the remaining gap is mainly the missing sibling differentiation and the unexplained 'scope' claim, which are modest given the surrounding structure.

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 both properties are documented as optional, so the schema already carries the parameter burden. The description only repeats the input names and adds the '13-digit' format hint, which is marginal value 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?

Names the required inputs (13-digit Corporate Number and a settlement IBAN) for a Japanese counterparty, so the resource is identifiable, but the actual action is never stated – it is implied by the tool name rather than a verb like 'verifies' or 'validates'. It also fails to distinguish itself from the sibling japan_corp_check or iban_check, which appear to cover overlapping ground.

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?

There is no statement of when to use this instead of japan_corp_check, iban_check, vendor_onboarding_pack, or the other *_supplier_check variants. A reader must infer that this is the combined Japan-specific pack, but the description never says so or gives any exclusions.

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