is_holiday

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

No annotations are provided, so the description must cover behavioral traits. It mentions country support and subdivision narrowing but does not disclose the return type (likely boolean), error handling for invalid dates or country codes, or any rate limits or side effects. The description is adequate but leaves some behavioral aspects implicit.

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: the first front-loads the purpose and usage context, the second adds practical details on parameters. Every sentence is necessary and concise, with no extraneous information.

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 tool is simple (3 parameters, no output schema), the description covers the main purpose, parameter details, and usage context. It does not explicitly state the return value (e.g., boolean), but that is implied for a holiday check. It is largely complete for its complexity level.

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%, so the schema already describes the parameters. The description adds value beyond the schema by providing examples of valid country codes (GB, US, ZA) and subdivision codes (SCT, WLS, NIR, US state), and noting the default for GB. This enhances understanding without being redundant.

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's purpose: checking if a date is a public/bank holiday for business-day deadlines, SLAs, or next working day. It specifies the resource (date) and the action (check holiday status), and distinguishes from siblings like 'next_holiday' by context. It also provides concrete use cases and examples of country codes.

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...' and gives clear contexts (business-day deadlines, delivery SLAs, next working day). It implies when to use it but does not explicitly state when not to use it or name alternatives like 'next_holiday'. The context is clear enough to guide selection.

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