calculate_belgian_income_tax

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

With no annotations, the description carries the full burden. It discloses the use of 2026 brackets and lists the return fields (income, tax_free_amount, etc.), providing good behavioral context. It could mention that it is a read-only calculation, but for a simple tax tool this is adequate.

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?

Two efficient sentences: first covers purpose and output, second points to related tools. No wasted words, information is front-loaded.

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?

Given one parameter with full schema coverage and the presence of an output schema (implied by listed return fields), the description is complete for a straightforward tax calculator. It includes the tax year and key output metrics.

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?

The input schema has 100% coverage, describing the 'income' parameter clearly. The description adds no additional parameter information beyond the schema, so baseline 3 is appropriate.

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 clearly states the tool calculates Belgian personal income tax using 2026 progressive brackets, specifying the verb and resource. It distinguishes itself from siblings as the only Belgian tax calculator in a list of many country-specific ones.

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 description hints at related calculators via list_bundles but does not provide explicit when-to-use or when-not-to-use guidance, nor alternatives. Usage is implied by the tool name and context.

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