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

Annotations already declare readOnlyHint=true and destructiveHint=false, covering the safety profile. The description adds meaningful behavioral context by stating that the return format differs from 'search' and that it is a legacy alias. This is beyond the annotations and helps an agent understand what to expect, though it doesn't detail the return structure.

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 in Japanese, front-loading the legacy status and the recommendation to use 'search'. It avoids unnecessary detail and is easy to parse, though it could be slightly more structured. Overall, it is efficient and focused.

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 tool with only two parameters and no output schema, the description provides the essential routing information (use 'search' instead) but lacks clarity on the return format—only that it is 'different'. Since the tool is deprecated, this might be acceptable, but an agent could still invoke it and would benefit from knowing what the response looks like. The description is minimally complete for calling the tool, but not fully informative.

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 50% (only 'query' has a description; 'limit' lacks one). The description adds no information about parameter semantics—it doesn't explain 'limit' behavior or how the query should be formatted. It fails to compensate for the missing schema documentation, leaving the agent without additional guidance on parameters.

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 clearly states the tool's purpose: it searches within the site (earthenware.jp) and explicitly differentiates from its sibling 'search' by noting a different return format. The verb and resource are specific, and the legacy status is clarified, removing ambiguity for an agent.

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 provides explicit guidance: it states this is a legacy tool kept for existing connections and instructs new users to use 'search' instead ('新しく使うときは search を使ってください'). This clearly communicates when not to use it and names the preferred alternative.

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