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

Annotations already declare readOnlyHint=true, openWorldHint=false, and destructiveHint=false, so the safety profile is covered. The description adds value beyond that by disclosing what each returned ASIN carries (brand, title, price/price range, fulfillment breakdown with amz/fba pct), which is useful since no output schema exists. It does not contradict the 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?

Three sentences with no filler: the core purpose is front-loaded, usage triggers come second, and the output-contents disclosure third. Every sentence earns its place, especially the last one given the missing output schema.

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 adequately covers the tool's purpose, trigger phrases, and result contents, which is enough to select and invoke it for the core 'brand' parameter. However, given the tool's high complexity (26 parameters, 31% schema coverage, no output schema), it leaves the agent without guidance on the many filter parameters, the effect of limit, or the interplay of since_days with first_seen_from.

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 only 31% across 26 parameters, so the description needed to compensate, but it documents no parameters directly. It only hints at price and fulfillment filtering through the output-content sentence. Most parameters (asin_contains, first_seen_from, max_seller_count, latest_buybox_seller, fulfillment pct filters, etc.) remain unexplained in both schema and description.

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 verb+resource+scope: 'Show ASINs that recently appeared for a brand.' The example user queries ('new products for Nike', 'recently added ASINs') reinforce the intent and help distinguish it from sibling tools focused on categories or operators (e.g., category_new_entrants, operator_new_brands).

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 explicit when-to-use guidance with concrete user-query examples and a catch-all ('or any question about a brand's recent catalog additions'). However, it does not state when not to use it or name alternative sibling tools, so it stops short of full exclusion guidance.

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