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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so few points remain to earn here. The description still adds genuine context beyond them: the exact governing formula, the weekend-baseline + authority-event rule, the fixed 2026 dataset window, and a concrete REST fallback path. Minor deduction for not clarifying error behavior if the date falls outside the covered year.

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 text is machine-bloated: 'Germany Germany', '2026-2026', and an output-field dump that the existing output schema already supplies. The docs link and REST fallback are useful, but the repetitive formula/example blocks and typos push this well past the size needed for a one-parameter date check.

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 single-date deterministic calculator with an output schema and full annotation coverage, the description does supply the deciding context: national scope, the fixed year, the exact formula, examples, and a fallback endpoint. It is complete in substance, though the garbled scope sentence and hard-coded 2026 window leave a small interpretive burden.

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?

Only one parameter, and schema description coverage is 100%, so the schema already documents 'date' as a Gregorian date in Germany coverage. The description repeats the parameter and supplies sample JSON arguments, adding convenience but no new semantics (no mention of valid range, timezone, or format edge cases). 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 states a specific operation (check a date against Germany's nationwide statutory holiday calendar) and enumerates the output fields, so the agent knows this is a date-check, not a count or add. However, the phrasing is garbled ('Germany Germany nationwide statutory public holidays for 2026 result') and never cleanly distinguishes itself from the add_de_working_days / count_de_working_days siblings that share the same calendar.

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 explicit when-to-use ('when you need a deterministic ... result', 'call this tool directly instead of answering from memory') and an intended scope exclusion, which is more than most tools offer. But the exclusion sentence is ungrammatical and ambiguous ('Do not use this when state, municipal, school, bank, TARGET ... schedules are not inferred'), and it never names the add_/count_ siblings as the alternative for range operations.

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