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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description consistently reinforces that ("확인만 하며 기관에 저장하거나 제출하지 않습니다"). It adds real context, namely the auth prerequisite and the per-call token cost ("호출마다 토큰 1소진"), but the long generic idempotency paragraph is boilerplate that does not fit a read-only check and muddies rather than clarifies retry behavior.

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 relevant content is two front-loaded sentences, but roughly half the text is a generic idempotency-key block (including the odd phrase "anonymous taste calls") that is irrelevant to a read-only pre-check. Mixed Korean/English also costs parseability, so every sentence does not earn its place.

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?

Auth, cost and non-mutating behavior are covered for a simple three-optional-parameter tool. However, with no output schema, the description never says what the check returns (a count? per-member rows?), leaving a gap an agent would want filled before calling.

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 explains up_cvrc_no, account_link_id and request_idempotency_key in detail. The description adds only indirect meaning, implying that up_cvrc_no is the parent receipt number to scope the pre-check; the baseline 3 applies when the schema carries the load.

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 Korean sentence states a specific verb and resource: before writing an acquisition report, check how many entries already exist under the parent receipt number. That cleanly separates it from the write-path siblings (acqs_init, acqs_save). It does not explicitly name those siblings, so it stops short of a 5.

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?

"자격취득 신고서를 쓰기 전에" gives an explicit precondition for calling it, and the REQUIRES line adds the login-with-same-account_link_id prerequisite. No explicit when-not or named alternative is given, which keeps it out of 5 territory.

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