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 that: the fields returned (address, phone, coordinates, services, hours) and the side effect that distance_miles is populated only when lat/lng are both supplied, plus ordering behavior when omitted.

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?

Two tightly packed sentences with no filler. The resource scope is front-loaded, followed by parameter behavior, so the most important information comes first.

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 spelled out, yet the description still previews the key directory fields. Combined with complete parameter semantics for a 3-param tool, nothing an agent needs to call it correctly is missing.

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 0%, so the description carries the full burden and does so: it enumerates the accepted site values (jcrew, factory) with the default (jcrew), and specifies that lat and lng must be given together, what that triggers (distance_miles), and the fallback ordering when both are omitted.

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: the 'full open-store directory' for J.Crew/J.Crew Factory. This clearly separates it from product/category siblings such as jcrew_product and jcrew_search, so an agent can identify it without opening the 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?

Gives conditional usage for each parameter (site selection, lat+lng pairing vs omission) and explains the resulting sort order. It does not name a sibling alternative to use instead, but the store-directory scope is distinct enough that explicit exclusions are not essential.

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