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

The description discloses substantial behavior beyond annotations: pre-validation via cached AI check, filtering to exact brand matches, fallback to returning brands that appeared in the keyword pool, and the mandatory output contract for 'Account notice' paragraphs. This is rich context that readOnlyHint/openWorldHint do not convey.

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 moderately long but well-structured: core purpose first, then mechanism, then fallback, then usage guidance, then a clearly delimited output contract. Each section earns its place, especially the mandatory output contract which is critical. No waste, though the 'How to use' and output contract could be seen as slightly verbose.

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 covers key output behaviors: no-match fallback and the 'Account notice' prefix. It explains the pre-validation and filtering. It doesn't describe result formatting or pagination, but those are covered by schema and typical tool patterns. Given the complexity (nested filters, 5 params), it is adequately complete.

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 80%, so the baseline is 3. The description adds high-level usage context (e.g., price range, revenue, reviews) that hints at how to use filters, but it doesn't provide specific parameter guidance beyond what the schema already offers. It adds marginal value.

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 clear verb+resource: 'List products under a specific Amazon brand.' It differentiates from siblings by focusing on brand-specific listing and explains the internal mechanism (pre-validates brand, filters keyword-search results). This makes the tool's unique role unmistakable.

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 provides explicit 'How to use' guidance: assess brand footprint (lineup breadth, price range, revenue carriers, review moat). This implies when to use it but doesn't explicitly name alternatives or exclusion criteria. Sibling differentiation is indirect, relying on the word 'brand' rather than naming search_products.

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