jp_calendar日本の祝日判定と営業日計算（内閣府「国民の祝日」CSV準拠）。営業日=土日・祝日以外。year_end_as_holiday=trueで12/29〜1/3も非営業日扱い。
| Name | Required | Description | Default |
|---|---|---|---|
| op | Yes | 操作種別 | |
| to | No | 期間終了日（list_holidaysで必須） | |
| date | No | 基準日 YYYY-MM-DD（list_holidays以外で必須） | |
| days | No | 加算する営業日数（add_business_daysで必須。負数=遡り、0=基準日をそのまま返す） | |
| from | No | 期間開始日（list_holidaysで必須） | |
| year_end_as_holiday | No | 12/29〜1/3を非営業日として扱う（官公庁・銀行休業の慣行。既定false=祝日法と土日のみ） |
Changes observed during successful MCP inspections. Dates show when Glama detected each change.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden and discloses key behavior: it follows the Cabinet Office CSV and treats weekends/holidays as non-business days. The year_end_as_holiday parameter behavior is also explained. It does not mention return types or edge cases, but for a calculation tool the core logic is transparent.
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, comprising two short sentences that front-load the purpose and immediately state the core rule and the special flag. Every clause contributes useful information without unnecessary verbosity.
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 tool's moderate complexity (6 parameters, 5 ops, no output schema), the description covers the essential behavioral rule and the optional flag. It lacks explicit return type descriptions, but the operation names (is_business_day, next_business_day, etc.) are self-explanatory, so completeness is adequate.
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%, so the baseline is 3. The description repeats the year_end_as_holiday semantics already present in the schema and adds the general business day rule, but does not significantly enrich parameter meanings beyond the existing schema descriptions.
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 function: '日本の祝日判定と営業日計算' (Japanese holiday determination and business day calculation), and defines the business day rule ('営業日=土日・祝日以外'). It uses specific verbs and a clear resource, and is distinctly different from sibling tools which focus on company/invoice verification.
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 gives clear context on when to use the tool by defining what counts as a business day and the optional year_end_as_holiday behavior. It does not explicitly exclude alternatives, but no sibling tool serves a similar purpose, so the usage is effectively clear.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.