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

Annotations already declare read-only, idempotent, non-destructive, and closed-world behavior, so the description adds domain-specific context beyond the safety profile: the weekend baseline, exact 2026-2027 authority events, formula, and REST fallback. It does not contradict the annotations, though the scope wording is somewhat confusing.

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 front-loaded with usage guidance, but it is overlong for a one-parameter deterministic checker and duplicates schema/output information such as input examples and output fields. Some phrasing, especially the 'Do not use this when...' sentence, is unclear and could be tightened.

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 annotations covering safety and an output schema covering return fields, the description supplies the remaining needed context: deterministic computation, 2026-2027 coverage, scope limitations, formula, examples, and fallback. It is largely complete, though the ambiguous exclusion sentence and redundant output listing keep it from being fully polished.

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?

The sole parameter is fully documented in the schema with a rich description of the Gregorian date and DGPA 2026-2027 coverage. The description adds only 'Inputs: date (date)' and JSON examples that duplicate the schema, so the baseline score of 3 is appropriate for high schema coverage.

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 identifies a specific verb-and-resource: checking a date against the Taiwan government administrative-agency working calendar for 2026-2027. It clearly states what is computed, but does not explicitly distinguish this tool from sibling check_*_working_day or add/count variants beyond the territory-specific name and title.

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?

It gives both a positive trigger ('Use this when you need a deterministic ... result') and scope exclusions (public enterprises generally follow the calendar, but special agencies, schools, private employers, banks, exchanges and sector schedules are not inferred). However, the exclusion sentence 'Do not use this when government administrative-agency scope only' is awkward and does not name an alternative tool for out-of-scope requests.

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