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

Annotations already declare readOnly/non-destructive, yet the description adds genuinely new behavior: per-call token cost ('호출마다 토큰 1소진'), idempotency-key lifecycle semantics, and the caveat that a provider-specific idempotency_key is a different field. What is missing is any statement about the result shape or listing limits, but the added context is substantial.

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 precondition is correctly front-loaded and the token-cost note is a good closing signal. But the middle is a dense idempotency paragraph with partially redundant sentences ('Without it, calling again remains a new request') that could be compressed to half its length.

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?

There is no output schema, so the description could carry return-value expectations (what a history entry contains, ordering, whether all entries or a page is returned), and it does not. The idempotency and precondition coverage is good, but the result side of a list tool is left entirely unspecified.

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 both parameters. The description still adds real meaning for request_idempotency_key — when to reuse it, when to generate a new one, and that anonymous calls cannot use it — going beyond the terse schema line that defers 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?

States a specific verb and resource ('List certificate application history'), which is clear in itself and separable from the detail/pdf siblings. However it never distinguishes itself from the adjacent list_init, detail_init, or history__detail tools, so an agent must still infer which one to call.

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?

Gives one real precondition ('REQUIRES prior fourinsure__session__login call with same account_link_id'), which is useful. But no when-to-use vs. the _init/history__detail variants, no guidance on paging or repeated listing, and no when-not-to-use case.

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