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

Annotations already declare readOnly, idempotent, openWorld, and non-destructive, so safety is covered. The description adds valuable context beyond annotations: the data source (Korea National Tax Service, real-time), the return values (active/suspended/closed + tax type), and the daily free-tier limit. It doesn't detail error behavior or rate-limit thresholds beyond the tier note.

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?

Three focused sentences front-loaded with the core purpose, followed by return values and a practical tip about the free tier. The free-tier example is slightly parenthetical but earns its place by aiding development.

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?

An output schema exists, so return values needn't be explained in depth, yet the description summarizes them anyway for agent convenience. Covers input, behavior, and data source. Missing explicit prerequisites (e.g., API key) and sibling differentiation, but otherwise complete for a single-param lookup 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 description coverage is 100% and the schema already specifies the 10-digit format, hyphen/space allowance, and an example. The description restates the parameter but adds no syntax or format details beyond the schema, so baseline 3 applies.

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 (check), resource (Korean business registration status), and the exact input (10-digit business registration number). Distinguishes from siblings like check_korean_business_batch (plural) and find_korean_business (search) by implying single-record lookup.

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?

Usage is implied (look up a specific business's status) but there are no explicit when-to-use/when-not statements or references to the sibling tools. An agent must infer that batch is for multiple numbers and find is for name-based lookup.

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