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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds genuinely new behavior: partial=true is returned with the remaining quotes when some exchanges fail to respond, and each call costs 30 points. It does not describe latency, rate limits, or how stale quotes are handled.

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 operative content (what it returns, the partial-result behavior, the cost) is front-loaded and each fact earns its place. The Korean sentence mostly restates the English one, which costs some density, but the bilingual pairing is a deliberate audience choice rather than filler.

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 carries the return-value burden: it states per-coin premium output and the partial=true degradation flag. It stops short of describing the response structure (per-exchange price fields, currency units), which would round out an agent's ability to consume the result.

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% — the single optional 'symbols' parameter is documented with comma-separated format, an example (BTC,ETH,XRP), and the default set. The description adds nothing about the parameter beyond what the schema already states, so the baseline 3 applies.

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 first sentence gives a specific verb chain and resource: compare Korean-won prices against global USDT prices and return the Korea premium per coin. This is unambiguous and instantly distinguishable from the sibling tools (account_realname, bank_code, transfer_1won), which belong to a different domain entirely.

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?

Usage is implied by the stated output (kimchi premium) but there is no explicit when-to-use or when-not-to-use guidance, nor any named alternative. The only routing-adjacent detail is the default symbol set when the argument is omitted, which is helpful but not a usage rule.

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