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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds the useful scoping detail that the tool is pinned to https://www.fashionnova.com, clarifying the data source, but says nothing about caching, freshness, or error behavior on a missing handle.

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?

A single front-loaded sentence with zero filler; the verb+resource and the domain pinning are stated immediately with nothing wasted.

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?

For a simple one-parameter read tool with an output schema (so return values need not be described) and read-only annotations, the description covers what is needed to invoke it correctly. Only the missing alternative-routing guidance keeps it from a 5.

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 100% and the sole parameter is fully documented in the schema as a required product handle/URL slug. The description's 'by handle' adds no syntax or format detail beyond the schema, so the baseline 3 is appropriate.

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?

States a specific verb+resource: 'product detail by handle', which is clearly a single-item detail fetch, distinguishing it in spirit from the sibling fashionnova_products (a list) and fashionnova_product_recommendations. It does not, however, explicitly name or differentiate itself from those siblings, so it falls short of a 5.

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 phrase 'by handle' implies you must already possess a handle, but the description gives no explicit when-to-use guidance, no prerequisites for obtaining a handle, and no routing to alternatives like fashionnova_products or fashionnova_search_suggest. Usage must be inferred.

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