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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so the safety profile is covered. The description adds genuinely useful behavior beyond that: the non-inference limits for ASN/local/sector/employee schedules, the deterministic per-date formula, an explicit REST fallback endpoint, and an auditable dataset_version/sources framing.

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?

Content is front-loaded and sectioned, but the 'Inputs', full JSON argument example, and the complete 'Outputs' field list largely duplicate the input schema, its example, and the output schema. Several lines do not add value beyond structured fields, so it is longer than necessary.

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 rich annotations and an output schema present, the description need not explain returns, yet it already covers scope, exclusions, formula, and fallback path. It is complete enough to invoke correctly, with the only gap being explicit disambiguation from the add_/check_ Indonesia 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% and the schema already documents types, defaults, and inclusion semantics for all four parameters. The description's 'Inputs:' line and JSON example merely restate the schema, adding no format or edge-case meaning beyond it, so 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 verb and resource with scope: 'Counts authority-scope working and non-working dates in a range,' and the JSON argument example pins down the input shape. Indonesia specificity plus 'authority-scope' distinguishes it from the wider country family, though it never explicitly contrasts with the adjacent add_id_working_days or check_id_working_day siblings.

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 an explicit when ('an auditable Indonesia working-day count') and a detailed when-not covering cuti bersama that is facultative for private employers and ASN-specific/local/sector/religious-optional schedules. No alternative tool is named for the excluded cases, so routing is clear on scope but not on the sibling to use instead.

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