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

Annotations already declare readOnlyHint=true and destructiveHint=false, so no contradiction exists. The description adds value beyond those hints by enumerating what the caller receives: identity, official URL, and resolved fields like prefecture, city, address, phone, and facility type.

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 focused sentence conveys the tool's purpose and return payload with no filler. The key action is front-loaded and every clause adds useful information.

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 simple, single-parameter lookup with strong annotations, the description provides enough detail about returned values to guide an agent. It does not describe missing-ID or error behavior, and 'such as' leaves the return list slightly open-ended, so it is not fully comprehensive.

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 schema already documents facility_id thoroughly with type, format, pattern, and a note that it is returned by search_facilities. The description only restates the parameter name without adding semantic detail, so baseline 3 is appropriate.

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?

The description states a specific action — 'Get one KIKARET facility by facility_id' — and names the resource clearly. It also lists the returned content, distinguishing it from search_facilities, which would return multiple facilities.

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 this tool is for fetching a single facility when you already have an ID, and the schema parameter notes that facility_id comes from search_facilities. It does not explicitly contrast with get_facility_knowledge or state when not to use it, so it falls short of a full 5.

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