is_public_holiday

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It discloses that the tool returns a summary string and a structured data object with the holiday name, type, and a chronological list of 2026–2027 holidays. However, it does not elaborate on error handling or edge cases (e.g., invalid dates or dates outside the listed range), so it is not fully 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 two sentences, front-loaded with the primary purpose and followed by a concise explanation of the return value. No unnecessary information is included, and each sentence earns its place.

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 that there is no output schema, the description sufficiently explains the return value (summary string and structured data object with holiday name, type, and holiday list) and the scope of the tool (regions and date check). It is complete enough for an agent to correctly select and invoke the tool.

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?

Both parameters are fully described in the input schema with clear descriptions and an enum for the region. The tool description adds no additional semantic information beyond what the schema already provides (e.g., it repeats the region list), so the baseline of 3 is appropriate.

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 ('Check whether') and resource ('a given date is a public holiday') and explicitly lists all supported regions, distinguishing it from sibling tools like get_school_term and get_next_business_day. It clearly identifies the tool's unique function.

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 (checking if a specific date is a public holiday in an ANZ region) but does not explicitly name alternatives or exclusion conditions. The purpose is clear enough to infer usage, but it stops short of explicit when-not guidance.

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