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 useful behavioral context by pinning the result to the row.gymshark.com storefront, implying region-specific pricing/availability. It does not mention auth, rate limits, or failure behavior when a handle is invalid, so it adds only partial value beyond 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?

A single compact sentence that front-loads the resource and ends with the region constraint. No wasted words, though it is arguably terse relative to the routing decision an agent faces among the gymshark siblings.

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 an output schema present, return values need not be described, and annotations cover the read-only/open-world profile. The description supplies the one piece of context not in structured data (the row.gymshark.com regional pin), so an agent has enough to call it correctly, though a note on obtaining handles would make it 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 coverage is 100% with a single well-documented parameter ('Required. Product handle (URL slug).'), so the schema already carries the semantics. The description repeats the handle concept but adds no format, normalization, or sourcing guidance beyond what the schema provides.

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 verb+resource (product detail by handle) and even discloses the region-pinned domain (row.gymshark.com), which is meaningful given the many regional storefronts. It does not explicitly distinguish itself from siblings like gymshark_products or gymshark_product_recommendations, 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?

There is no explicit when-to-use guidance, no mention of alternatives (e.g. gymshark_products for browsing, gymshark_collections for category-wide lookups), and no stated prerequisite that a handle must first be obtained from a listing tool. Usage is only implied by the phrase 'product detail by handle'.

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