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

Annotations already declare readOnlyHint/idempotentHint/destructiveHint/openWorldHint, so the safety profile is covered. The description adds one genuinely useful non-schema fact — that the service is independent of the sellers it reports on — but says nothing about behavior on an unknown seller name, return shape, or data freshness.

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 deliverable list is front-loaded and each metric earns its place, but the entire content is written twice (English then Korean), roughly doubling length for identical information. The affiliate disclaimer is also repeated verbatim in both languages.

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 does the work of outlining what comes back — three named metric groups tied to the seller — which is enough for an agent to decide and call. It stops short of describing units, cell format, or empty-result behavior.

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?

Only one parameter (seller) at 100% schema description coverage, including Korean example values, so the schema carries the semantics. The description adds no extra meaning about the seller identifier (e.g., exact-match vs alias, case sensitivity).

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 the concrete outputs for a seller: price-change frequency (increases/decreases), sold-out option ratio, and the country/day cells where it is cheapest. An agent can tell this is a seller-level metric lookup, though it never states the verb ('return/get') nor distinguishes itself from the sibling get_price_trend, which overlaps on price-change data.

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?

No when-to-use guidance is given: no condition that selects this over get_price_trend (price changes), find_esim_prices (current prices), or compare_countries. The only routing-adjacent sentence is the affiliation disclaimer, which is about trust, not tool selection.

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