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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds genuine behavioral context: the storefront is fixed/public and takes no URL, plus the return is normalized metadata. It stops short of permissions or rate-limit detail, but that is minor for a zero-argument read of a fixed endpoint.

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, followed by the routing alternatives. Every clause carries information; there is no filler.

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 described. For a zero-argument, read-only, fixed-endpoint tool, the description plus annotations and output schema give the agent everything needed 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?

Zero parameters, so there are no parameter semantics to document and the baseline is 4. The description reinforces this by stating no store URL is accepted, heading off an attempt to supply one.

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 ("Fetch store details") and resource (Pristine Marketplace's fixed public storefront), and adds the scope qualifier that it is a single fixed storefront with normalized metadata. An agent can distinguish this from pristine_marketplace_search/product/page without opening any 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 the agent to four named alternatives (search for discovery, product for one item, page for page content, sitemaps for sitemap discovery) and adds the exclusion "no store URL is accepted" that selects this tool over a parameterized store lookup. Nothing is left to inference.

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