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

Annotations already declare the safe, idempotent, closed-world read profile, but the description adds meaningful context beyond them: the pinned 2026 dataset/snapshot limitation, the explicit declaration that later legal changes require a new snapshot, what it intentionally does not infer (substitute Mondays, payroll premiums, leave rights), and a REST fallback path. This is substantive behavioral disclosure not present in the annotations.

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 long and unevenly structured: the broken 'Do not use this when' sentence hurts readability, and the Outputs enumeration is largely redundant given an output schema exists. The 'What it computes' and 'Formula' parts are useful and front-loaded, but overall it is verbose rather than tight.

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 date-range count tool with an output schema and full annotation coverage, the definition supplies more than enough: scope, policy disclaimers, formula, worked JSON example, and a REST/docs pointer. The main gap is that it does not route the agent away from the closely-related check_/add_ Slovakia siblings.

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 all four parameters (start_date, end_date, and the two include_* toggles). The description restates the inputs and gives a JSON example but adds no semantics beyond the schema, so the baseline 3 is appropriate.

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 clearly states the verb+resource+scope: 'Counts authority-scope working and non-working dates in a range' for Slovakia, and the name/title confirm the territory. It is specific about what is counted (rest-day holidays vs named holidays), though it never names the obvious siblings (check_sk_working_day, add_sk_working_days) to differentiate this range-counting tool from them.

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?

There is an explicit 'Use this when' clause ('auditable Slovakia working-day count', 'return its calculation instead of answering from memory'), which is useful. However the 'Do not use this when' clause is garbled ('Do not use this when pinned Slovakia 2026 statutory rest-day layer over an explicitly declared Monday-Friday planning baseline, not an individual roster') and reads as a broken sentence rather than clear exclusion criteria. Alternatives are not named, so usage is only partially guided.

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