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

Annotations only cover readOnly/destructive, so the description carries the real burden: it discloses the NPKI certificate auth mechanism, per-call token consumption ('호출마다 토큰 1소진'), and retry/recovery semantics for lost responses. It stops short of saying what a successful login yields or how long the session lasts.

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?

The critical directive is correctly front-loaded, but the idempotency block runs long and repeats the same idea several ways ('Without it, calling again remains a new request'), plus an unexplained Korean cost line at the end. It earns its place but could be half the length.

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 an auth tool with no output schema and only one required business number, the description covers entry conditions, cost, and retry semantics adequately. The one meaningful omission is what a successful call returns or how the resulting session is referenced by later tools.

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 coverage is 100%, so baseline is 3, but the description genuinely adds meaning for request_idempotency_key — that reusing the same key with the same arguments only recovers a prior request, and omitting it makes a retry a brand-new execution. It also warns that a provider-specific idempotency_key is a distinct field.

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 and resource — login to NPS EDI via NPKI certificate — and the opening sentence explicitly positions it as the prerequisite action for this provider, which separates it from siblings like nps_edi__auth__session__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?

'Call this FIRST before any other tool for this provider' gives an unambiguous ordering constraint, and the idempotency paragraph spells out when to reuse the key versus mint a new one. Nothing about when-to-call is left to inference.

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