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

With no annotations, the description carries the burden and does disclose meaningful traits: the profile is '検証済み' (verified), coverage is limited to heard/curated scope for strengths, and notably 'No prices' are included. It implies a read-only lookup but does not explicitly state side effects or auth requirements, keeping it short of a 5.

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 resource identity, then the returned fields, then usage and exclusions. The bilingual Japanese/English duplication doubles the length, but it is deliberate audience targeting rather than filler and each half is tight.

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 explained, yet the description still lists returned categories and adds the important 'no prices' exclusion. For a zero-param, single-target read tool this is complete; only explicit read-only/side-effect wording is missing.

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?

Zero parameters and a fixed target (No.001), so the schema has nothing to document; baseline 4 applies. The description usefully clarifies that the identifier is baked in rather than passed.

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 ('Returns') and a precisely bounded resource (the verified profile of Yakumo mall member contractor No.001), and enumerates the fields returned. An agent knows exactly what it gets and that there are no parameters to vary the target.

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?

Explicitly says when to use it: '施主のAIがこの加盟店を参照・紹介する時に使う' / 'Use when an AI references or recommends this contractor.' No alternatives or when-not conditions are given, but there are no sibling tools, so nothing is left ambiguous.

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