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

Annotations already mark this as read-only and non-destructive, and the description adds valuable behavioral context: token cost per marketplace, the exact data returned, and the mandatory 'Account notice:' output contract with verbatim copy requirements. This goes well beyond the structured annotations.

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 a crisp purpose sentence and is organized into clear sections for behavior, cost, usage, and output contract. It is somewhat long, and the grouping instruction is repeated from the schema, but every section earns its place given the mandatory account-notice handling.

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 there is no output schema, the description compensates fully by specifying the returned fields, the marketplace list, cost, and the exact handling of account-notice results. It also tells the agent how to continue the workflow if the user later wants analysis, so nothing needed for correct invocation is missing.

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 single parameter 'asins' is fully documented in the input schema with format, count, and grouping guidance, so the schema carries the burden. The description adds little beyond 'per ASIN' and largely duplicates the schema's 'Pass several only when they will be analyzed together' instruction, keeping this at 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 states a specific action with a resource: find which Amazon marketplaces list an ASIN and get its product link on every marketplace. It also enumerates the return fields (title, local price, estimated monthly sales), making the tool's purpose unmistakable and distinguishable from siblings like analyze_product or search_products.

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 gives an explicit invocation condition: call it ONLY when the user asks where a product is sold or wants links on other marketplaces. It also provides a clear exclusion — do not call it just to choose a marketplace for analysis — and routes follow-up analysis to amzscout_analyze_product / amzscout_get_keywords.

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