tax_rate

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

Discloses that the tool is date-sensitive, handles historical/temporary changes, and explains US behavior (returns 0 without state code). With no annotations, the description effectively conveys key behavioral traits beyond the schema.

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 concise (4 sentences) with no redundant information. It front-loads the primary purpose, then adds key details about date-sensitivity and US handling.

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?

Covers usage for both GB and US, parameter guidance, and date-sensitive nature. However, it does not describe the output format (e.g., numeric rate, currency symbol), which could be inferred but is not explicit.

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?

Despite 0% schema coverage, the description explains each parameter: country defaults to GB, date is the invoice date, state is for US. It provides context for when to use each, compensating for the lack of schema descriptions.

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 'Look up the correct consumption-tax rate' and specifies it's for VAT/sales tax. It distinguishes from sibling tools (none cover tax rates) by providing precise use-case and geographic variations.

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?

Explicitly says 'USE THIS before calculating VAT or sales tax on an invoice or quote — never recall the rate from memory', giving clear when-to-use advice. It does not mention alternatives, but no sibling tool provides tax rates, so the guidance is sufficient.

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