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

Annotations supply readOnlyHint=true and openWorldHint=true, so the safety profile is already covered. The description adds the non-obvious fact that this reads a *fixed* public storefront rather than a parameterized one, which is genuine context beyond the annotations. It doesn't discuss rate limits or caching, but those are minor here.

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 sentences, front-loaded with the core action and scope, then the sibling routing. No filler or repetition.

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, the description need not explain return values; it covers purpose, scope, sibling selection, and the no-input constraint. Nothing an agent needs to invoke 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?

Zero parameters, so the baseline is 4. The description clarifies that no storefront URL input is needed, which preempts an agent expecting a URL parameter — useful semantic framing for a correctly empty schema.

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 ('Fetch store details for Fashion Nova's fixed public storefront, including its normalized storefront metadata'). It then names three sibling tools and the exact resource each covers, so an agent can tell it apart from fashionnova_products/collections/page 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?

Explicitly routes to fashionnova_products for catalog items, fashionnova_collections for collection groups, and fashionnova_page for page content, and clarifies that no storefront URL input is needed. It states when to use alternatives but not when *not* to use this tool (e.g. no filtering by store).

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