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

With no annotations, the description carries the full burden. It does disclose what is returned (all published fields: capacity, accepted ages, opening hours, corporate info), which is valuable since there is no output schema, but it says nothing about behavior on a nonexistent/invalid ID or about read-only semantics beyond the verb 取得.

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?

A single front-loaded sentence with no filler. The parenthetical field list earns its place by previewing the return payload, though the ID format detail duplicates the schema pattern.

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?

For a one-parameter read tool with no annotations and no output schema, the description covers the input format, the scope (one record), and the shape of the returned data. Only error/not-found behavior is left unstated, a minor gap at this complexity.

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 schema already documents the ID, its 16-hex-digit pattern, and that it comes from search_childcare_facilities. The description restates the 16-digit hex format, adding redundancy rather than new meaning, so the 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 (取得) and resource (保育施設), and the scope is explicit: exactly one facility looked up by ID, returning all published fields. This clearly separates it from the search_* siblings, though it never names them.

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?

The description implies usage ('specify the ID to get one facility'), which makes the lookup-by-ID pattern inferable, and the schema notes that IDs come from search_childcare_facilities. There is no explicit when-to-use vs when-not guidance or named alternative in the description itself.

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