Update mail account

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

Annotations already declare idempotentHint and openWorldHint. The description adds behavioral detail that omitted fields are not changed, which is consistent and adds context. No contradictions are present.

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 extremely concise with just two sentences, front-loaded with the core action, and no redundant information. Every word serves a purpose.

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?

Given no output schema, the description does not explain return values, which is acceptable for a simple update. It adequately covers the input behavior and is supplemented by rich annotations and sibling context.

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 coverage is 100% with detailed parameter descriptions. The tool description's note about preserving omitted fields adds general context, but it doesn't significantly enhance understanding of individual parameters beyond what the schema provides.

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 explicitly states 'partially update mail account settings' (メールアカウントの設定を部分更新する), clearly defining the verb and resource. It distinguishes itself from sibling tools like create_mail_account and delete_mail_account by emphasizing partial update.

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 clear context that omitted fields preserve current values, guiding an agent to only send changed fields. While it doesn't explicitly mention when not to use this tool, the sibling tool names imply its role for modification rather than creation or deletion.

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