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

The description discloses payment requirements ($0.01 per call via x402), a 6-day trial on first paid call, and retry instructions. However, it does not mention rate limits, data freshness, or whether the operation has side effects beyond payment.

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 description is front-loaded with the core purpose and is clear, though it includes verbose payment details that could be slightly condensed. Every sentence adds value.

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?

The description covers purpose, ranking, payment, trial, and cold start advice, but does not specify the return format (e.g., array of district names or objects), which is a gap given no output schema.

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 already describes the single parameter 'limit' with default 5 and max 25. The tool description adds no extra meaning beyond ranking all districts first, so baseline score 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 description clearly states that the tool scans all 25 Seoul districts and returns those currently at a top (overheated, sell), ranked most-top first. This distinguishes it from siblings like scan_bottoms and pitch.

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?

The description provides explicit guidance: it is best for a cold start as no symbol selection is needed, and points to the pitch tool for counting. It also explains payment and retry behavior.

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