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

Without relying on the annotations, it discloses that each call consumes one token, creates an XBOSS job, persists the result, and is not purely read-only — consistent with readOnlyHint=false. The idempotency paragraph explains retry semantics (reuse key only to recover a lost response, new key for new execution), which is valuable context not encoded anywhere else. The closing Korean sentences are vague about what actually changes.

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 is correctly front-loaded and the idempotency rule is spelled out clearly. However, the multi-sentence idempotency treatment is disproportionate for an optional recovery key, and the trailing Korean boilerplate about XBOSS and '기관 데이터 변경' is generic and low-information.

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 nine-parameter tool with no output schema, the description omits what the retro payment result contains (rounds, amounts, period covered) and how row_key/row_index are meant to be sourced from a prior list call. The operational behavior (token, job creation, persistence) is covered, so the gap is in result-shape expectations rather than invocation mechanics.

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 the schema already documents all nine parameters. The description adds only two things: that account_link_id must match the login session, and that request_idempotency_key is a distinct field from any provider-specific idempotency_key. Nothing is said about how row_key, row_index, or template_code select the retro payment record.

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 second sentence states a specific verb and resource — 'Get retro pension premium payments' — matching the Korean title 국민연금 소급분 조회. It is distinguishable from siblings such as payment_history or summary, though the description never explicitly contrasts with them.

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 clearly states a prerequisite (prior nps_edi__auth__npki_session__login with the same account_link_id), which is real when-to-use guidance. But it gives no guidance on choosing between this and the other national_pension_premiums lookups (summary, payment_history, subscribers, guide).

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