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

Annotations already cover read-only and open-world semantics, and the description adds genuinely new behavioral context: a per-call price ($0.01 USDC), the payment rail (x402 on Base), and the upstream data source. It stops at 4 because nothing is said about how partial or invalid entries inside a batch of 100 are handled, which is the main failure mode for a batch tool.

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?

A single front-loaded sentence: capability and batch limit first, then the enumerated return values, then source and cost. No filler or restated name/title.

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?

With no output schema and one parameter, the description does the heavy lifting by enumerating the possible status values and the VAT-type output, plus live-source and pricing context. Missing are the input number format and batch error semantics, which an agent would need to call it confidently at scale.

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 0%, so the description carries the burden; it tells the agent these are Korean business numbers and reinforces the 100-item ceiling (already in maxItems). It adds no format guidance (hyphenation, digit count) or array-of-strings example, so it only partially compensates for the coverage gap.

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?

Names a specific verb+resource ('business registration check'), enumerates the returned statuses (active, suspended, closed, not registered) and VAT type, and its batch scope of up to 100 numbers cleanly distinguishes it from the singular kr_business_status sibling.

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?

'up to 100 ... in one call' establishes the context in which this tool is preferred over a single-lookup tool, and being 'live from the National Tax Service' signals freshness. It never explicitly names kr_business_status as the single-number alternative or states any exclusion, so it stops short of a 5.

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