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

No annotations are provided, so the description carries the full behavioral burden. It does disclose the authoritative data source (人事行政總處辦公日曆) and the content categories covered, but says nothing about return shape, pagination, supported year ranges, or behavior for out-of-range years. For a read-only lookup tool that is acceptable but not rich.

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?

A single front-loaded sentence covering the resource, the data source, and the special cases, with no filler. It is dense but readable; the only mild cost is that the embedded clause about 'today' blurs scope with the is_holiday sibling.

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 read-only lookup with one optional parameter and no output schema, the description covers the data source and the categories returned, which is what an agent needs to call it. It stops short of explaining how years are validated or what happens for unsupported years, but nothing critical is missing.

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% and the single optional 'year' parameter is already documented in the schema. The description's mention of today's status and the next long weekend hints at the default behavior when year is omitted, but adds no syntax or format detail beyond the schema. Baseline 3 applies.

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 names a specific verb and resource: retrieving Taiwan national holidays, 連假, and 補班日 from the 人事行政總處 office calendar, plus today's holiday status and the next long weekend. That is clearly distinguishable from the other siblings (invoice, lottery, fuel). However, it does not distinguish itself from its closest sibling is_holiday, whose scope (today's holiday status) is explicitly folded into this tool's description.

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?

Usage is only implied: the tool returns holiday calendars and 'today' status, so an agent can infer it is the general holiday-lookup. There is no explicit statement of when to prefer this over is_holiday, nor any exclusion or prerequisite guidance, despite is_holiday being an obvious alternative.

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