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

Annotations already signal read-only and non-destructive behavior. The description adds legacy status and the fact that behavior matches 'search' but with a different return shape, which is useful context beyond annotations. However, it does not disclose any additional behavioral details (e.g., performance, rate limits) that might matter.

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 description is two concise sentences, each earning its place: the first establishes the legacy context and the second clarifies the relationship to 'search' and gives explicit usage guidance. The critical guidance (use search) is front-loaded and repeated, making it easy for an agent to act on.

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 legacy alias tool with no output schema, the description explains the tool's purpose and routing clearly, but omits the specific return format difference, which would be needed for an agent to fully understand invocation results. Given the tool's deprecated nature and the explicit push toward 'search', this is adequate but not wholly complete.

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 provides a description for 'query' (50% coverage), and the 'limit' parameter is documented via its default/min/max constraints. The description adds no parameter-specific semantics beyond saying it searches 'like search', offering no details on how query or limit behave differently or are formatted. With only 50% schema coverage, the description should compensate but does not.

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 (search inside the site) and resource (prenica.jp), and explicitly distinguishes itself from the sibling 'search' by noting the return format is different. However, it does not specify what the return format actually is, leaving slight ambiguity about the exact output.

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 explicitly states to use 'search' for new usage ('新しく使うときは search を使ってください'), clearly identifying the alternative and the condition under which this legacy tool should be used. This leaves no ambiguity about when to invoke this tool versus 'search'.

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