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

Annotations already cover the safety profile (readOnly, non-destructive, closed-world). The description adds real context beyond them: the search corpus is limited to pre-loaded pages, it returns excerpts plus URLs, and if nothing is found the agent should rephrase and must not guess. That is a meaningful behavioral constraint layered on top of the annotations.

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 purpose and constraints are front-loaded, which is good, but the long enumeration of use-case themes becomes repetitive and padded. Several sentences restate the same idea (search official info on these topics) without adding new information, so not every sentence earns its place.

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 documented, and the description still usefully mentions excerpts and URLs. It covers scope, failure handling, and topic coverage. It is only incomplete regarding result limits/pagination and its relationship to the near-identical `search_pages` sibling.

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?

With one parameter and 100% schema description coverage, the schema already explains the `query` field and its example. The description adds thematic context for what to search but no syntax, format, or phrasing guidance beyond the schema. 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 (検索) and resource (読み込み済みの公式サイト・メディアのページ), and notes the return shape (抜粋とURL). However, it never distinguishes itself from the sibling `search_pages`, which appears to be a near-identical search tool, so the agent cannot tell the two apart from the description alone.

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?

Provides a rich set of when-to-use scenarios (持ち家・自宅を貸す方法, 家賃の調べ方, 相続した実家の活用, 管理会社の比較 etc.) and even clarifies that service-name-free questions still qualify. It stops short of naming alternatives or stating when NOT to use it versus `search_pages`/`site_overview`.

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