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

Annotations already declare readOnlyHint=true and destructiveHint=false, yet the description still adds genuinely useful behavior: the auth/session dependency, per-call token consumption ('호출마다 토큰 1소진'), and full idempotency semantics including that an omitted key makes every retry a new request. It stops short of saying what the selection produces or whether it persists state.

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?

Roughly two-thirds of the text is generic, reusable idempotency boilerplate that applies to every tool in this family, including an aside about 'anonymous taste calls' and a note about provider-specific idempotency_key fields that no parameter here exposes. The one sentence of actual tool-specific purpose is crowded between boilerplate blocks.

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 6-parameter readOnly tool with full schema coverage and no output schema, the auth and cost context is adequate. What is missing is the outcome of the call — whether it returns a candidate list to choose from or commits a selection used by the detail tool — which matters for a tool literally named select.

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 documents insurance_year, worker_name, birth_ymd, account_link_id and business_management_no; the description adds no format detail beyond that. The only parameter the description elaborates on is request_idempotency_key, and even there the schema already carries the pattern, bounds and a pointer back to the description.

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 sentence 'Search and select a worker for COMWEL individual billed-premium inquiry' gives a specific verb plus resource and scopes it to a lookup step, which distinguishes it from the sibling comwel__info__individual_billed_premium__detail. The purpose is however buried after a prerequisite sentence and before a long generic idempotency block, so it is clear once found but not front-and-center.

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 states a hard prerequisite ('REQUIRES prior comwel__auth__npki_session__login call with same account_link_id') and explains when to reuse vs. regenerate the idempotency key. What it never says is when to pick this tool over the sibling detail tool, or whether worker_select is a mandatory precondition for the detail call — the agent must infer the ordering.

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