list_storefronts

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

With no annotations, the description carries the full burden, and it does disclose what the response enumerates plus two non-obvious domain quirks (Italian MediaMarkt = MediaWorld; Saturn is Germany only) that an agent could not derive from structured fields. The behavioral surface is small for a zero-argument read, so the remaining gap — no explicit statement that it is a safe, side-effect-free read — is minor.

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 short sentences, front-loaded with the primary content enumeration before the caveats. Each sentence carries information, though the MediaWorld/Saturn details are narrow edge cases that could be folded into a single caveat sentence.

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 no explanation, and with zero parameters the definition is nearly complete. The only meaningful omission is an explicit statement of the ordering relationship with the sibling search/lookup tools, which is left implicit through the country-specificity remark.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate; baseline 4 applies. The notes about country-specific IDs and retailer naming are relevant domain context but do not map to any input.

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?

The description opens with a specific verb and an explicit enumeration of the resource set: supported countries, retailers, shop languages, currencies and delivery-filter availability. That is enough to distinguish it from find_stores and search_products, which look up actual stores/products rather than the storefront taxonomy. It stops short of naming those siblings directly, so it lands at 4 rather than 5.

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?

Usage is only implied: 'Product and store IDs are country-specific' hints that an agent should consult this list before issuing country-scoped lookups, and the MediaWorld/Saturn notes hint at resolving naming before searching. There is no explicit 'call this first' instruction or statement of when not to use it versus find_stores or search_products. The guidance is inferable but not spelled out.

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