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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered; the description adds genuinely non-derivable context: the session prerequisite, the per-call cost note ("호출마다 토큰 1소진"), and retry semantics for idempotency. It still says nothing about result volume or paging behavior despite page_num/page_size existing.

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, but the idempotency paragraph is long and boilerplate-like for what is a read-only search, and the trailing Korean cost note is untranslated amid otherwise English prose. Sentences earn their place individually, but the balance is skewed toward recovery-key mechanics over search semantics.

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 an 8-parameter read tool with no output schema, the description covers the auth prerequisite, the filtering identifiers, cost, and retry behavior. The remaining gap is what the returned sales records look like and how pagination should be driven, which an agent must infer.

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 3 baseline applies to bsno/stl_yr/qrt_from/qrt_to. The description earns a bump because it carries the idempotency-key contract the schema explicitly defers to it ("see the tool description"), including reuse-only-for-recovery and new-key-per-execution rules that the field cannot convey alone.

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 names a specific verb and resource ("Search credit card sales data") and pairs it with the data scope parameters (business number, settlement year, quarter range). It does not explicitly distinguish this from similarly named siblings such as hometax__cash_receipt__sales__search_history, but the credit-card-sales scope is unambiguous on its own.

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?

"REQUIRES prior hometax__session__login call with same account_link_id" gives an explicit precondition that would otherwise be discovered only by failure. It stops short of stating when to prefer a different tool or what to do when no card sales exist for the period, so no true when-not guidance is present.

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