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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the read-only safety profile is covered. The description adds operational constraints (platform key, server env flag) and does not contradict annotations, but it does not describe response behavior or failure modes.

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 short sentences, each earning its place: the first states the action, the second specifies auth mode, and the third gives a server prerequisite. No filler or redundancy.

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 one-parameter, read-only lookup tool, the description is complete: the schema covers the parameter, annotations cover safety, and the description covers the API source, auth requirement, and environment flag. No output schema exists, but the return value is not needed to invoke the tool correctly.

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%: b_no is fully documented with format, min/max length, item count limits, and an example. The description adds no parameter-specific meaning, so the baseline of 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?

States a specific verb ('Look up'), a clear resource ('NTS business registration status'), and identifies the underlying data.go.kr API by reference number. However, it does not explicitly distinguish itself from similar sibling tools like opendata__nts__validate or hometax__tax__business_registration__search_status.

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?

Provides concrete usage context: this uses a platform service key, requires no account_link_id, and needs OPENDATA_ENABLED=1 on the server. This tells an agent when the open-data route is applicable, though it does not enumerate exclusions or alternatives.

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