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

Annotations already cover the safety profile (readOnly, idempotent, closed-world), so the description is free to add domain behaviour: vakantietoeslag is included, kostendelersnorm only counts medebewoners aged 27+, the own home is exempt up to the statutory limit, and no arbeidskorting is applied because norms are already net. That is meaningful context beyond the annotations, though return shape and edge-case handling remain unstated (output schema likely covers returns).

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 computed result, then usage, then exclusions, then a precision caveat. Dense but no sentence is filler; only minor compression would be possible.

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 7-parameter calculation tool with an output schema (so returns need not be described), the description supplies scope, exclusions, and the main computational rules. The only thin spot is that per-field interpretation of medebewoner_leeftijden and inkomsten is only partially spelled out in prose.

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?

With 71% schema coverage the baseline is 3, but the description adds real semantics: it clarifies that medebewoners only matter from 27+, that vermogen excludes the own home against a statutory threshold, and that netto inkomsten are offset against the norm. These map directly onto the leefvorm/vermogen/overwaarde/medebewoner inputs.

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?

It names the exact computed output ('Netto bijstandsnorm per maand (incl. vakantietoeslag) volgens de Participatiewet') and enumerates the mechanisms it applies (kostendelersnorm, verrekening netto inkomsten, vermogenstoets). The scope boundaries ('Niet voor jongerennormen (18-20), bijzondere bijstand of gemeentelijke regelingen') carve it away from adjacent concepts an agent might confuse it with.

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?

Explicit routing both ways: 'Gebruik bij vragen over bijstand of sociaal minimum vanaf 21 jaar' states the trigger, and the following sentence lists the exclusions (18-20 normen, bijzondere bijstand, gemeentelijke regelingen). Nothing is left to inference about when this tool applies.

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