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

With no annotations, the description bears full burden. It discloses the read-only nature ('List everything...') and the lack of auth requirement. For a simple listing tool, this is transparent, though it omits potential details like response format or pagination.

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 with no extraneous words. The description is front-loaded with the main purpose and includes specific detail (domain name, item types, auth requirement).

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?

Given the tool's simplicity (zero parameters, no output schema), the description provides essential context: what the tool lists and that no auth is needed. It could mention how the results relate to sibling tools like store_buy, but it is largely complete.

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% (no parameters exist). The description adds no parameter-specific information, which is acceptable as there are none. Baseline score of 3 applies.

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 explicitly states it lists everything for sale at a specific domain, specifying the types of items (agent templates and API credit packs). It distinguishes from siblings like store_buy (purchasing) and store_download_template (downloading).

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?

The description clearly implies this tool is for browsing available items before purchase, and notes that no authentication is needed. While it doesn't explicitly list when not to use it, the context from sibling tools makes it straightforward.

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