list_holidays

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

No annotations are present, so the description carries the disclosure burden. It usefully reveals the returned item fields and the country default/ISO support, but it does not disclose edge cases such as invalid country handling, sorting, or possible variation in holiday types by country.

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?

Three concise sentences with the core action front-loaded, followed by useful output-shape and country-scope details. There is minor redundancy with the schema default, but no wasted words of consequence.

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 two-parameter list tool with no output schema, the description conveys enough to make a correct call: year is required, country is optional with a default, and returned items contain date and name fields. It could add return-format details like date type or sorting, but those are not essential for basic invocation.

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 baseline is 3. The description adds output-context but does not add new parameter semantics beyond what the schema already states; year is only documented as '4-digit year' in the 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 states a specific verb ('List'), a clear resource ('public holidays'), and a scope ('in a given year'), and it previews the output fields. It does not explicitly contrast with siblings, but 'all ... in a given year' distinguishes it from single-date or next-holiday tools.

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 this tool is for full-year enumeration rather than single-date checks like is_holiday or next_holidays, but it never says when to prefer it or when to use an alternative. The guidance is inferred rather than explicit.

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