defaults_invoice

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

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint=false, so safety profile is covered. The description adds useful context beyond annotations: the exact data domains returned and the BNR exchange-rate source, which matters for invoice correctness.

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 tight sentences: purpose and returned contents front-loaded, then the usage directive. Every clause carries information; no filler.

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?

Although there is no output schema, the description enumerates the returned value categories in enough detail that an agent knows what to expect. Combined with annotations and full schema coverage, nothing material 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 description coverage is 100%, so the companyId override is already documented in the schema. The description adds no additional parameter semantics, which is acceptable at baseline 3.

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 verb+resource (get default values and dropdown options for invoice creation) and enumerates exactly what comes back (VAT rates, currencies, payment terms, units, methods, BNR rates). Clearly distinct from siblings like vat_rates_list or exchange_rates_list, which return single data sets.

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?

Gives an explicit directive: 'Always fetch this before creating invoices — never hardcode these values.' That establishes the when and a strong anti-pattern, though it does not name alternative tools for individual value sets.

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