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

Goes well past the annotations (readOnlyHint=false, destructiveHint=false, which alone leave ambiguity): it clarifies that nothing is submitted, discloses the side effect that 'some programmes save the draft between screens' and that safety.save_executed reports it, and quantifies cost ('호출마다 토큰 1소진'). The idempotency-key recovery semantics and the distinction from provider-specific idempotency_key are additional behavior an agent cannot infer from structured fields.

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 hard prerequisite and the no-submission guarantee are front-loaded, and each paragraph covers a distinct concern (auth, behavior, idempotency, cost). The idempotency passage is long and repeats the anonymous-call caveat, costing a bit of tightness but not clarity.

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?

With no output schema, the description carries the return burden and does so: attachment set, whether submission is allowed, and safety.save_executed. Auth prerequisite, cost, and idempotency are all covered; only expected failure modes (e.g. what an invalid draft returns) are unaddressed.

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 baseline is 3; the description adds value by tying account_link_id to the required login session and by fully explaining request_idempotency_key (the schema itself defers to the description: 'see the tool description'). It does not explain how programme_key and receipt_no relate to prior calls beyond the schema's own notes.

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 a draft) and resource (work24 subsidy application), and explicitly contrasts with the submission step: 'Nothing is submitted - this is the mandatory check before submit.' The title in Korean matches, and an agent can distinguish it from work24__subsidy__application__submit without opening either schema.

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?

Names the precondition ('REQUIRES prior work24__auth__npki_session__login call with same account_link_id') and the position in the workflow ('mandatory check before submit'). It does not explicitly say when validation can be skipped or what to do if validation fails, so it stops just short of full when/when-not guidance.

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