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

Annotations already declare readOnlyHint=true and idempotentHint=true, so a safe compute operation is expected. The description adds value beyond those annotations by disclosing the calculation behavior: the exact benefit rates, the basis on SV-loon, and the 'maximumdagloon als grens' (maximum daily wage cap). No contradiction with annotations is present.

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?

A single, front-loaded sentence delivers the verb, resource, basis, the three rates, and the cap with zero filler. Every element earns its place, and the computation logic is packed efficiently without sacrificing clarity.

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 straightforward calculator with two fully documented parameters and read-only/idempotent annotations, the description is largely complete: it covers all variants, rates, and the cap. The only gap is the absence of any hint about the output format/return shape, but since there is no output schema and the computation logic is fully specified, this is a minor omission.

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% — grossMonthlySalary ('Laatstverdiende bruto maandsalaris in euro vóór arbeidsongeschiktheid') and includesHolidayPay ('8% vakantiegeld zit al in het opgegeven bruto maandsalaris') are both fully documented in the schema. The description's 'SV-loon' concept adds a framing term but no new syntactic or format detail. Baseline 3 is appropriate since the schema carries the parameter semantics.

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 ('Berekent' = calculates), a distinct resource ('WIA-uitkering 2026'), and enumerates the three benefit variants with explicit rates (IVA 75%, WGA-loongerelateerd 70%, WGA-vervolg) plus the maximum daily wage cap. This clearly differentiates the tool from siblings like nmi_ww_uitkering (WW benefit) and the bruto/netto calculators without needing to inspect their schemas.

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?

Usage is only implied: an agent can infer this is the tool for WIA benefit calculation because the benefit type is named, which distinguishes it from the WW sibling. However, there is no explicit when-to-use / when-not-to-use guidance, no mention of prerequisites (e.g., the SV-loon context), and no alternatives named. Sibling differentiation is left to the consumer.

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