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

With readOnlyHint=true already covering the safety profile, the description adds meaningful behavioral context: real-time nature, reverse-premium and surge alerts, and the payment requirement ('Paid in USDC on Base'). These are traits an agent cannot infer from annotations or schema alone.

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?

Three efficient sentences each serve a distinct purpose: when to use, what it reports, and cost basis. The content is front-loaded and free of filler or repetition of structured schema details.

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?

Given one optional parameter, read-only annotations, and an output schema, the description supplies the remaining needed context: scope, exclusions, alert behavior, and payment. It could name an alternative sibling for excluded cases, but that is a nice-to-have rather than essential for invoking the tool correctly.

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?

The input schema fully documents the single symbol parameter, including examples and a default value, so description coverage is 100%. The tool description adds no extra parameter-level semantics beyond the schema, matching the baseline.

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 opens with a specific use case—'evaluating Korean exchange price premiums, the kimchi premium, Upbit price gaps vs Binance/OKX'—and names the resource and behavior: real-time Upbit vs global price spread with reverse-premium and surge alerts. It also differentiates from siblings by explicitly excluding general USD spot prices and DEX swaps.

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 gives a clear when-to-use trigger list and explicit exclusions ('Do not use for general USD spot prices or on-chain DEX swaps'). However, it does not name a sibling alternative tool for those excluded cases, so it falls just short of full guidance.

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