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

With no annotations, the description carries the full load and does much of it: it discloses the per-call cost ($0.03 USDC via x402), the fact that premium_usdt_pct is a gross spot comparison ignoring spreads, fees, liquidity and transfer constraints, and the 10-symbol cap. It omits auth/rate-limit behavior and whether the call is cached or real-time.

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?

Front-loads the core purpose before the caveats and cost, and every sentence carries information. The parenthetical comparing the two bases is dense but justified given the sign-disagreement warning.

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?

No output schema and no annotations, yet the description names both return fields and their derivation, plus cost and the symbol limit — enough for an agent to call and interpret it. Missing only operational details like freshness or rate limits.

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% and the single optional parameter is fully documented in the schema, so the baseline is 3. The description adds only the max-10 cap on symbols, a minor increment over the schema's format and default.

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 metric (kimchi premium) and enumerates the exact two outputs it computes, premium_official_pct and premium_usdt_pct, each tied to a named rate source. An agent can distinguish this from fx_usdkrw or crypto_krw_ticker purely from the description.

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?

Explains the semantics of the two bases and warns that their signs frequently disagree, which implicitly tells the agent when each number is meaningful. However, it never states when to pick this tool over kimchi_premium_history, kimchi_premium_stats, or preview_kimchi_premium, and gives no exclusions.

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