N営業日後/前の日付

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

The description goes far beyond the readOnlyHint annotation by detailing the counting logic: weekends and holidays are excluded, the start date is excluded from the count, zero is an invalid input, and the default start date is today in Japan time. These are critical behavioral details that affect how the agent invokes and interprets the tool.

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 well-structured passage that front-loads the core purpose and then lists the key rules in sequence. Every clause provides relevant information, with no filler or redundancy.

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 simplicity of the tool (two parameters, no output schema), the description covers all essential aspects: the calculation rule, sign semantics, holiday handling, start-date exclusion, invalid days, and default date. It does not specify the return format, but that is implicitly a date string and not necessary given the 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?

The input schema already provides complete descriptions for both parameters (100% coverage), and the description largely restates them in prose. It adds one important non-schema constraint — that days cannot be zero — and clarifies that the start date itself is not counted, which provides marginal added value over the schema.

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 it calculates the date N business days after or before a specified date, using a specific verb ('計算します') and resource (business days). The sign convention for days is explicit, and the behavior distinguishes it from sibling tools like jp_is_business_day or jp_business_days_between, even though it does not name them.

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 for when to use the tool (when you need to offset a date by business days) and includes important rules like excluding weekends/holidays and that the start date is not counted. However, it does not explicitly mention alternatives or when not to use it, so the agent must infer that from the sibling tool names.

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