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

Annotations already declare readOnly/idempotent/non-destructive, yet the description still adds real substance: what data_confidence levels mean, that sources are law URLs with a data_version, and that output carries a not-legal-advice disclaimer. Minor gap: it does not clarify how in_probation changes the computation, though the UAE rules summary hints at it.

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?

Purpose, rules, example, and response contract are front-loaded in a tight sequence with no filler. The response-field enumeration is slightly dense but each item (legal_basis, data_confidence semantics, warnings) carries information.

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 annotations and an output schema present, the description need not restate safety or return structure, and it still summarizes both. The single remaining hole is in_probation, which neither the schema nor the description explains, keeping it from a 5.

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 coverage is 75%, so the schema already documents country (with law versions), days, and monthly_wage; the example confirms their shape. However, in_probation has an empty schema description and is not mentioned in the description at all, leaving both channels silent on a parameter that materially affects the result (none paid during probation in UAE).

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?

States a specific act (pay for N sick days) plus the governing tiered rule set for each country, naming the exact articles. An agent can distinguish it from annual_leave_entitlement, end_of_service, or overtime_pay without opening any schema.

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?

The worked example (country 'AE', days 40, monthly_wage 9000) makes the intended invocation concrete and implies the domain boundaries. It does not explicitly say when to prefer a sibling or exclude cases (e.g., sick leave spanning employment termination), so it stops short of a 5.

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