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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds worthwhile operational context beyond annotations: the data.go.kr source identifier, the 'platform service key only' requirement, and the OPENDATA_ENABLED server flag. It does not disclose response format, but that is a smaller gap given the read-only validation nature.

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 with no filler: purpose, required fields, key/flag prerequisites. All meaningful constraints are front-loaded, and every sentence contributes information an agent needs before calling the tool.

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 single-parameter validation tool with read-only annotations, the description covers the non-obvious prerequisites: external data source, required per-item fields, auth mode, and environment flag. A response-form semantics mention would slightly improve it since there is no output schema, but the definition is otherwise complete for correct invocation.

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 b_no, start_dt, p_nm and optional fields. The description reinforces the required trio and adds the YYYYMMDD format for start_dt, but does not materially go beyond what the input schema already communicates, so 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 states a specific action ('Validate') on a specific resource ('NTS business registration identity') and identifies the exact upstream API (data.go.kr 15081808). This clearly differentiates it from sibling tools like opendata__nts__status, which would be a status lookup rather than a validation.

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 concrete invocation context: which fields must be present per array item, that only a platform service key is accepted, that account_link_id is not used, and that the server must have OPENDATA_ENABLED=1. It does not explicitly name alternatives or exclusions, but the context is clear enough to prevent misuse.

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