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

Even though annotations already declare readOnlyHint/idempotentHint/openWorldHint, the description adds genuinely valuable behavioral context: results may be served from a cache up to 24 hours old and are marked 'cache': true, order is preserved, a summary count is returned, and the data source is Korea National Tax Service. The cache-staleness disclosure is exactly the kind of gotcha that annotations cannot express.

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?

Four sentences, each earning its place: purpose and limit first, then return shape, then usage routing, then cache behavior and data source. No filler or repetition of schema content.

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 a single parameter, 100% schema coverage, an output schema present, and safety annotations already supplied, the description covers all remaining decision-relevant context: batch limit, cache semantics, ordering guarantees, and data provenance. Nothing an agent needs to select and invoke this tool correctly 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% — the schema already documents the array type, 1-100 count, and that hyphens/spaces are allowed, so baseline is 3. The description adds the '10-digit' format constraint and the Korean term 사업자등록번호, which help an agent validate inputs beyond what the schema states.

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 states a specific verb ('Check'), a concrete resource ('registration status ... of Korean businesses'), and a clear scope ('up to 100 ... in a single call'). It also names the key identifier format (10-digit 사업자등록번호), which makes the tool's function unmistakable and distinct from a single-check tool.

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?

The description gives explicit routing guidance: 'Use this instead of repeated single checks when screening supplier or customer lists.' This clearly selects this tool over the single-check sibling check_korean_business_status. However, it does not state when not to use it or how it relates to the third sibling, verify_korean_business, so exclusions are incomplete.

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