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

Annotations only say readOnlyHint=false and destructiveHint=false, so the description carries the burden of behavior disclosure. It does so well: the empty-row semantics ('not a certified no sanction ever claim') is a genuinely important interpretation guardrail, and it surfaces the server-side service-key and OPENDATA_ENABLED=1 requirements. This is valuable context beyond the schema. It does not contradict 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?

Three dense sentences with no filler; purpose is front-loaded and each subsequent sentence earns its place (interpretation guardrail, then operational prerequisites). Slightly technical phrasing (API ids, env flags) but efficient for this domain.

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?

For a moderately complex tool with no output schema, the description covers purpose, the authoritative source, the key parameter, the key caveat, and operational prerequisites. Its only gap is that it doesn't describe the response/return structure or pagination beyond what the schema implies, which matters more given the absence of an output schema. Still, the core calling guidance is complete.

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%, so the schema already documents all five parameters (bizno, pageNo, numOfRows, inqryBgnDt, inqryEndDt). The description reinforces that bizno is the key lookup identifier via 'inqryDiv=1 + bizno', which is a slight value-add, but it doesn't explain the date-format semantics or pagination defaults beyond what the schema already states. Baseline 3 is appropriate.

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 names a specific verb ('Look up'), a specific resource (G2B unfair-supplier sanction records), and pins the exact upstream API (data.go.kr 15129466 getUnptRsttCorpInfo02, inqryDiv=1 + bizno). This clearly differentiates it from sibling sanction tools like opendata__env__waste_sanction and opendata__kiscon__sanction, which are distinct data sources.

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 operational constraints (platform service key only, no account_link_id, OPENDATA_ENABLED=1 required) that condition use, and a critical semantic caveat about empty results. However, it never tells an agent when to pick this tool over the sibling sanction lookups (env waste, kiscon), so differentiation from alternatives is left implicit rather than explicit.

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