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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered. The description adds real behavioral context beyond them: the storefront URL is fixed server-side and valid empty result pages return 200 with an empty array, which preempts a common 'is this an error?' misread.

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?

Front-loaded with the core behavior and the storefront, followed by edge-case behavior and the sibling pointer. It is efficient overall, though restating the parameter defaults verbatim is mildly redundant with the 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?

An output schema exists, so return values need not be explained. For a two-param read tool the description covers scope, fixed endpoint, empty-page semantics, pagination caps, and sibling routing—everything an agent needs to call it correctly.

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 description merely restates the same limit/page defaults (50/250, 1-based, default 1) already in the schema. Baseline 3 is appropriate since the schema carries the parameter detail and the description adds nothing new.

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 ('Returns normalized collections from Gymshark') and even fixes the storefront (row.gymshark.com). It explicitly names the sibling gymshark_collection_products, letting an agent distinguish this from the products variant without opening a schema.

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 closing sentence routes the agent to gymshark_collection_products for the product-listing use case, which is clear alternative guidance. It doesn't state an explicit 'when to use this instead' beyond that one sibling, so it falls short of a full 5.

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