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

Annotations already declare readOnlyHint and openWorldHint, so the description's job is to add situational detail. It does so by specifying which surfaces are returned (desktop and mobile variants) and that region selects the storefront, though it says nothing about caching, load cost, or whether missing regions error out.

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?

Three sentences, front-loaded with the return payload, then the routing rule, then the parameter default. No filler or redundant restatement of the tool name.

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-shape explanation is unnecessary. Combined with annotations covering safety and the explicit sibling routing, nothing an agent needs to call this 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 100%, and the description duplicates the enum list and 'defaults to my' verbatim from the schema. Since the schema already carries the parameter semantics fully, baseline 3 applies – no additional insight is added.

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 and resource ('Get one Shopee storefront's footer layout') and enumerates the concrete contents (desktop/mobile blocks, section titles, help/about links, partner images, social links, QR codes). This is distinguishable at a glance from shopee_home, shopee_banners, and shopee_shop_info.

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?

Explicitly gives the motivating use case ('harvest support or policy urls') and names the alternative with its own use case ('prefer shopee_home for merchandising modules'). Both the when-to-use and the when-not-to-use are present.

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