get_vat_exemption_threshold

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

Annotations already declare readOnlyHint and idempotentHint. The description adds behavioral context by stating 'Information provided as reference only — not legal advice,' which sets expectations for the reliability of the output. No contradictions with annotations.

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?

The description is extremely concise: two sentences that pack the purpose, usage, output structure, and legal disclaimer without any wasted words. It is front-loaded with the primary function.

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 the tool's simplicity (one parameter, output schema exists), the description covers all necessary aspects: what it returns, when to use it, and a disclaimer. No gaps are evident for an AI agent to correctly invoke this tool.

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% with a single parameter described. The description adds marginal value by specifying 'European country' and providing example codes ('PT', 'DE', 'FR'), but the schema already covers the required format. The baseline of 3 is appropriate as the description does not significantly enhance parameter understanding.

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?

Description clearly states the verb 'returns', the resource (annual turnover threshold for VAT exemption), and the scope (European country). It also explicitly distinguishes this from sibling tools by naming the specific VAT scheme and mentioning the output structure.

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?

Description explicitly says when to use the tool: 'when determining if a small business needs to register for VAT, or when building onboarding flows for European freelancers and micro-enterprises.' It does not explicitly state when not to use, but the guidance is clear enough for an agent to infer appropriate contexts.

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