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

Annotations already declare readOnly, idempotent, closed-world and non-destructive, so the description is free to add value elsewhere — and it does, disclosing the rules year (2026), last-updated date, authoritative page URL, and the shape of the response (result rows in page language, raw engine outputs, sources with lastChecked, disclaimer). It stops short of stating precision/rounding or error behaviour, which keeps it from a 5.

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?

Front-loaded with the resource and formula, then the rules year and return shape, with no filler. The trailing sentence about "Only used when" inputs is slightly cryptic and would read better near the parameters, but it is short and does earn its place.

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 two-input, no-output-schema calculator, the definition covers inputs, calculation rule, version freshness and return contents well enough to call it correctly. It could add the validity range of the salary input or what happens below/above the cap, but nothing essential is 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 coverage is 100% and both parameters are fully documented in the schema, including the enum mapping non/oui to 80%/85%, so the baseline of 3 applies. The description's rate formula does explain why enfantACharge matters, but adds no syntax or format detail beyond 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 definition names a specific resource (Luxembourg full unemployment benefit / ADEM) and states the calculation basis (80–85% of average gross salary, capped by multiples of the social minimum wage). Country-specific naming separates it cleanly from greece_unemployment_benefit and the other siblings, though it never uses an explicit verb like "calculates".

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 implied by the country and benefit name rather than stated: nothing says when to pick this over greece_unemployment_benefit or list_calculators. The only routing hint is the closing note that inputs marked "Only used when" apply conditionally, which is parameter guidance rather than tool selection guidance.

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