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. Beyond that, the description supplies the auth requirement ('Platform service key only — no account_link_id'), which is exactly the kind of platform-routing context the rubric credits and is not present in the schema or annotations. It stops short of describing how batch failures or partial matches are reported.

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?

Two sentences, front-loaded with the action and dataset ID, then the required inputs and credential constraint — no filler or marketing language. Slight overlap with the schema on required fields is the only wasted space.

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, read-only tool with 100% schema coverage this is adequate to invoke correctly, but with no output schema the description never says what the validation response looks like (per-business valid/invalid, partial results, failure modes). It also leaves the boundary with the sibling opendata__nts__status unstated.

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 nested item fields (b_no, start_dt, p_nm, plus optional ones) are documented there with lengths and the YYYYMMDD format. The description restates the required trio and the 'per businesses[] item' batching, which is accurate but largely redundant, so the 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 ('Validate') plus the exact resource ('NTS business registration identity') and even cites the source dataset (data.go.kr 15081808), so the agent knows precisely what is checked. It does not, however, differentiate itself from the sibling opendata__nts__status, which shares the same NTS namespace and whose scope the description never contrasts.

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?

Implied usage only: 'Validate NTS business registration identity' tells you this is a verification call, and the note 'Platform service key only — no account_link_id' is a genuine invocation constraint that steers credential selection. However, there is no explicit when-to-use/when-not guidance and no routing hint versus opendata__nts__status or the hometax business-registration siblings.

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