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

Beyond the readOnly/non-destructive annotations, the description adds genuinely new behavior: it explicitly says nothing is stored or submitted to the institution, states a per-call cost ('호출마다 토큰 1소진'), and describes the return payload since there is no output schema. The idempotency paragraph is verbose and reads as mandatory while the schema marks the key optional, which is a minor internal inconsistency rather than an annotation conflict.

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 prerequisite, purpose, and read-only statement are well front-loaded, but roughly half the text is a four-sentence idempotency-key digression that crowds out the core lookup semantics, and the mixing of English and Korean adds friction.

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 usefully summarizes the returned values, plus prerequisites, read-only nature, and token cost — everything an agent needs to call it correctly. Only the sibling relationship to acqs_precheck/acqs_init remains 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 coverage is already 100%, so the baseline is 3; the description earns an extra point by explaining that applicant_name + resident_registration_number are the lookup keys and by tying account_link_id to the login session it must match. The idempotency-key explanation largely restates and lengthens what the schema already says.

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 verb and resource ('성명과 주민등록번호로 가입자를 조회해') and even enumerates the returned fields (rrkey, 대표자 여부, 보험별 자격취득일·상실일). It implicitly separates itself from the qualification-write siblings ('자격취득 신고서를 쓰기 전에') but never names acqs_init/acqs_precheck/los_member_lookup explicitly.

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?

It gives a clear call context (call this before writing the acquisition report) and a hard prerequisite ('REQUIRES prior fourinsure__session__login call with same account_link_id'). What is missing is any mention of the nearby alternatives such as acqs_precheck or los_member_lookup, which an agent could easily confuse this with.

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