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

Annotations already declare `readOnlyHint=true`, `idempotentHint=true`, and `destructiveHint=false`, covering the safety and idempotency profile. The description adds that products come from 'the configured trusted merchant catalog', which is a minor detail about the source. No additional behavioral traits (e.g., pagination, rate limits, ordering) are mentioned. With strong annotation coverage, the description's extra value is limited, resulting in a baseline score.

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?

The description consists of exactly two sentences. The first sentence states the core action and scope, and the second provides actionable usage guidance. Every sentence earns its place; there is no fluff. The structure is front-loaded and highly efficient.

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 (0 parameters, rich annotations, presence of an output schema), the description is complete. It explains what the tool does and how the returned data should be used. The output schema handles return value details. No gaps remain for a list operation with no parameters.

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 has zero parameters, and schema coverage is trivially 100%. The description does not need to add parameter semantics, and it doesn't. Per the guidelines, with 0 parameters the baseline is 4. The description simply omits any parameter discussion, which is appropriate.

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 uses the specific verb 'Lists' and identifies the resource as 'products from the configured trusted merchant catalog'. It also mentions using the returned IDs for 'product lookup or checkout', which distinguishes it from sibling tools like `vibecart.get_product` (single product) and `vibecart.create_checkout` (checkout action). The purpose is clear and unambiguous.

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 provides explicit guidance on how the output should be used ('Use the returned stable IDs for product lookup or checkout'), which implies when to use this tool (to obtain product IDs before further operations). However, it does not explicitly state when not to use it or directly compare with alternatives like `vibecart.get_product`. The context is clear but lacks explicit exclusions.

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