Zaim API MCP Server

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states it's a read operation ('取得します' - get), which implies non-destructive behavior, but doesn't mention any behavioral traits like authentication requirements, rate limits, or what the output looks like. For a tool with zero annotation coverage, this is a significant gap, as it doesn't add context beyond the basic purpose.

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 a single, efficient sentence in Japanese that directly states the purpose. It's appropriately sized and front-loaded with the key action and resource. There's no wasted text, but it could be slightly more structured if it included brief usage hints, though it's not necessary for conciseness.

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 the complexity (a read operation with one parameter) and no annotations or output schema, the description is incomplete. It doesn't explain what the tool returns (e.g., list format, fields) or any behavioral aspects like error handling. For a tool with no structured data to rely on, the description should provide more context to be fully helpful, making it inadequate.

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 description adds minimal meaning beyond the input schema. It mentions '支出または収入' (expense or income), which aligns with the 'mode' parameter's enum values ('payment' and 'income'), but the schema already has 100% coverage with a clear description for 'mode.' With high schema coverage, the baseline is 3, and the description doesn't compensate with additional details like parameter constraints or examples, so it meets the minimum viable standard.

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: 'Zaimのデフォルトカテゴリ一覧を取得します（支出または収入）' translates to 'Get Zaim's default category list (expense or income).' It specifies the verb ('取得します' - get) and resource ('デフォルトカテゴリ一覧' - default category list), and distinguishes it from siblings like 'zaim_get_user_categories' by specifying 'default' categories. However, it doesn't explicitly contrast with all siblings, such as 'zaim_get_default_genres,' which is similar but for genres, so it's not a perfect 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?

The description implies usage by mentioning '支出または収入' (expense or income), which relates to the 'mode' parameter, but it doesn't provide explicit guidance on when to use this tool versus alternatives. For example, it doesn't clarify when to use 'zaim_get_default_categories' versus 'zaim_get_user_categories' or 'zaim_get_default_genres.' The context is clear but lacks explicit when/when-not statements or named alternatives, so it's adequate but with gaps.

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