List public holiday and custom day patterns

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

Annotations only declare readOnlyHint and openWorldHint; the description adds a genuinely useful limitation: the API exposes pattern names only and 'the dates inside a pattern are not exposed by API V2'. That pre-empts an agent expecting date data, which the annotations do not convey.

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, front-loaded with the primary resource and output shape, and the API limitation is placed last as a caveat. The first sentence is dense but every clause carries 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?

With no output schema, the description usefully states the return shape ('as id and name') and a key data limitation. Both parameters are covered by the schema, so the only gap is that include_contact_details' redaction behavior is never surfaced in prose.

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 documents both booleans; baseline is 3. The description adds an example of what include_custom_days returns ('Christmas Shutdown') but says nothing about include_contact_details and its unusual redaction-stripping semantics.

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?

Specific verb plus resource: it lists 'public holiday patterns held in the system' and, with a flag, 'custom day patterns', with concrete examples of each. The resource is clearly distinct from the sibling list tools (groups, absence types, users), though no sibling is named explicitly.

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 phrase 'with include_custom_days, the custom day patterns' implies when the optional mode applies, but there is no explicit when-to-use/when-not guidance or naming of an alternative tool. Usage is inferable rather than stated.

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