Yakumo verified contractor No.002: Mineo Toyo Juki Co., Ltd. (Shonan, Japan)

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

No annotations are supplied, so the description carries the full burden, and it does disclose meaningful behavioral facts: an explicit content exclusion ('No prices'), a hard geographic restriction ('Japan only'), the notion that profile fields are gated by verification/fill state ('検証済み', 'プロフィール充足度', 'ヒアリングで整備された範囲'), and the provenance of the strengths data. It still omits operational traits such as freshness/live-vs-cached data and any permission or rate-limit considerations, which keeps it below 5 for an annotation-free tool.

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 entity name and the returned-field scope are front-loaded, and every element is substantive rather than filler. The main cost is the full Japanese/English duplication, which roughly doubles the length and repeats the same content, though that duplication serves a deliberate bilingual audience.

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 is not obliged to enumerate return fields, yet its enumeration usefully signals scope and the explicit 'No prices' exclusion. For a zero-parameter, single-entity read tool this covers everything an agent needs to select and invoke 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?

The input schema declares zero properties and the tool takes no arguments, which is the documented baseline of 4. The description appropriately spends no words on parameters, and its statement that the profile is fixed to member No.002 implicitly explains why no identifier is required.

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 precise verb ('returns') and a precisely identified resource: the verified profile of the specific contractor 'Mineo Toyo Juki Co., Ltd.' (No.002), with an explicit enumeration of what the profile contains. There is no ambiguity about what an agent gets back, and the scoping phrase 'No prices' rules out the most likely confusion with a pricing tool.

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 a clear usage condition: 'Use when an AI references or recommends this contractor' (施主のAIがこの加盟店を参照・紹介する時に使う). That is a concrete trigger, not just implied usage. It stops short of 5 because there are no alternatives or when-not conditions to route against (no siblings exist), so no exclusion criteria are stated.

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