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

Annotations already declare this as a read-only, idempotent, non-destructive, closed-world operation. The description adds useful behavioral context: 2026-2027 coverage, the exact weekend/authority-event formula, the deterministic nature, and the warning that CAO, sector, employer, school, bank, and municipal schedules are not inferred.

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 heavily over-specified for a one-parameter check tool. It redundantly lists output fields despite an output schema, repeats JSON examples, and includes REST fallback and docs details that inflate the text without improving selection or invocation.

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?

Given the simple schema, output schema, and annotations, the description is sufficiently complete: it defines the coverage window, deterministic formula, limitations, and direct invocation expectation. The only shortfall is that its verbosity and garbled opening sentence add noise rather than missing context.

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 date parameter is already documented in the schema as a Gregorian date in Netherlands coverage. The description repeats the input name and adds examples, but it does not add meaningful syntax or constraint information beyond 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 and resource: it checks a date against the Netherlands working-day baseline and 2026-2027 authority events. The country scope distinguishes it from other country-specific check tools, though the opening phrase 'Netherlands Netherlands official public holidays' is garbled and briefly misstates what the tool returns.

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 a use case and a caveat about not inferring CAO/contract-dependent day-off status, but the guidance is awkwardly worded and does not explicitly compare this tool to sibling alternatives such as count_nl_working_days or add_nl_working_days. The agent is told to call it directly, but the when-not-to-use condition is more of a domain limitation than a routing rule.

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