holiday_business_days_between

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the agent knows it is a safe read operation. The description adds a useful behavioral detail (inclusive of neither endpoint by default), but does not disclose what happens if dates are reversed or whether Japanese holidays/weekends are excluded, though the name implies it.

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 entire description is one sentence, front-loaded with the action and ending with a concise parenthetical about endpoint behavior. Every word earns its place; no fluff 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?

For a simple read-only counting tool, the description captures the essential behavior and default inclusivity. The annotations cover safety, and the schema fully documents parameters. It could be improved by explicitly stating that Japanese holidays and weekends are excluded, but the name and phrase 'Japanese business days' largely carry that meaning.

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%, with both 'from' and 'to' clearly described as YYYY-MM-DD dates. The tool description adds minimal value beyond the schema, only reinforcing that these are the two endpoints, 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?

The description uses a specific verb ('Count') and resource ('Japanese business days between two dates'), making the action unmistakable. It also clarifies the endpoint inclusivity default, which distinguishes it from related holiday tools like holiday_is_holiday or holiday_add_business_days.

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 usage context is implied: the tool is for counting business days between a start and end date. However, it does not explicitly mention when to use it over alternatives, such as holiday_is_holiday for single-day checks or holiday_add_business_days for adding days.

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