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

Annotations already declare read-only, idempotent, non-destructive behavior, and the description adds substantial context beyond that: exclusions for Christmas Eve, Easter Eve, etc., Saturday/Sunday handling, the calculation formula, and the REST fallback. It also warns not to guess other API paths.

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 organized into labeled sections and front-loads the main use case, but it is verbose for a two-parameter calculation tool. The list of output fields is redundant given the existing output schema, and some sentences could be removed without losing invocation guidance.

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 annotations, full input-schema coverage, and output schema, the description is complete: it covers when to use the tool, what it excludes, how it computes the result, an example call, output expectations, and a REST fallback. Nothing essential for correct invocation appears to be 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 description mostly repeats the inputs ('start_date (date); working_days (integer)') and provides a JSON example that mirrors the schema. The formula adds algorithm context, but parameter-specific semantics are already fully covered by 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 the specific operation ('Adds or subtracts Norway authority-scope working days') and names the jurisdiction, making it easy to distinguish from the many country-specific siblings. It also clarifies the deterministic offset use case rather than merely restating the tool name.

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 clear when-to-use condition ('when you need a deterministic Norway working-day offset') and an explicit exclusion for nationwide statutory full-day lists and related closures. It does not, however, name the sibling alternatives such as check_no_working_day or count_no_working_days, so routing is not fully specified.

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