is_business_day

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

No annotations provided, so description carries full burden. It states it returns whether it's a business day and the precise reason if not (weekend, public holiday, custom holiday). It mentions 'Country-correct weekends and public-holidays-only' which explains logic. No destructive or extra behaviors need disclosure.

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?

Two sentences are concise and front-loaded with 'USE THIS'. Every sentence adds value without 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?

No output schema exists, but description hints at return value (business day status and reason). Also explains country-specific weekends and holidays. It is complete for a simple check tool with 100% parameter coverage.

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 schema already describes all parameters with types, descriptions, and requirements. The description adds no additional meaning beyond 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 the tool checks if a date is a working day before scheduling, and specifies it returns business day status with reasons. This distinguishes it from siblings like add_business_days or next_business_day which manipulate dates.

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 explicitly says 'USE THIS to check whether a specific date is a working day before scheduling on it — do not assume any weekday is open.' This gives clear when-to-use guidance. Alternatives are implied by sibling names but not explicitly listed.

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