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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds genuine value by enumerating the returned fields (type, introduction, loaded page count, main pages), which matters because there is no output schema. It does not state whether the overview reflects a live crawl or a cached index snapshot, which is the remaining gap.

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?

Three compact sentences with zero waste: the return content is stated first, then the field breakdown, then the usage trigger. Everything is front-loaded and each sentence carries distinct 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?

With no parameters, no output schema, and annotations covering the safety profile, the description carries the burden of explaining return values and does so adequately. It stops short of clarifying data freshness or whether the site must be preloaded before an overview is available.

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 tool takes zero parameters, so the baseline of 4 applies and there is nothing to document. The description does not need to compensate for any schema gaps.

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 names a specific resource (the codenate.jp site) and states precisely what is returned: site type, introduction text, number of loaded pages, and main pages. This clearly separates it from siblings like list_pages or search, which operate on individual pages rather than the site as a whole. It does not explicitly name a sibling, so a 4 rather than a 5.

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?

It gives a clear usage condition: use it first when you want to grasp the overall picture of the site (「最初にサイトの全体像をつかみたいときに使います」). There are no explicit exclusions or named alternatives, but the 'first' framing implies an orientation step before fetch/get_page/search.

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