holiday_add_business_days

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

Annotations already provide readOnlyHint and openWorldHint, so the safe read-only nature is disclosed. The description adds critical behavioral context by stating that weekends and public holidays are skipped, and that the holiday calendar is Japanese. This goes beyond the annotations, though it does not cover edge cases like starting date falling on a holiday or timezone handling.

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, grammatically complete sentence that front-loads the operation (Add or subtract) and then specifies the subject (Japanese business days) and behavior (skipping weekends and holidays). Every part of the sentence carries meaning, with zero waste.

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?

With only 2 simple parameters fully described in the schema, the description provides sufficient context for the tool's core purpose and behavior. No output schema exists, but the return value (a shifted date) is easily inferred from the tool name and description. The tool is self-contained and does not require additional explanation.

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 100%: both parameters have clear descriptions ('Start date, YYYY-MM-DD' and 'Business days to add (-3650 to 3650); negative subtracts'). The tool description adds no additional meaning beyond the schema, so the baseline of 3 applies.

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?

Description clearly states a specific verb+resource: 'Add (or subtract) a number of Japanese business days to a date'. It distinguishes from sibling tools like holiday_business_days_between by focusing on shifting a date rather than counting days between dates. The scope (Japanese business days, skipping weekends/holidays) is explicit.

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 when to use the tool (when you need to shift a date by business days) but does not explicitly mention alternatives or exclusions. Sibling tools exist (e.g., holiday_business_days_between) but are not referenced, leaving the agent to infer the distinction based on the operation described.

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