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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety is covered. The description still adds genuine value: the required READ:PRODUCT scope, the underlying endpoint, the returned fields, and the next_offset pagination loop that the agent must continue.

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 tight sentences, front-loaded with what is returned before the auth and endpoint details. Every clause carries information: contents, return shape, pagination instruction, permission, and route.

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 no output schema, the description correctly compensates by naming the returned fields (products, discounts, next_offset) and the auth scope. The only remaining gap is that it does not clarify how 'library' relates to the other product/inventory listing siblings.

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%, and both parameters are fully documented in the schema, including the default of 100 and the 1-500 range. The description's pagination hint ('pass it back as offset') duplicates what the offset schema description already says, so it adds no meaning beyond the structured data.

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 resource ('product library') plus the distinguishing scope 'together with its discounts (name, amount or percentage)', which differentiates it from a plain product listing. It does not explicitly name which sibling (e.g. zettle_list_products) it supersedes, so the separation is implied rather than stated.

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 context is implied: use this when you need products and their discounts in one paginated call, and the 'pass it back as offset' note gives a concrete pagination pattern. However, it never states when to prefer this over zettle_list_products or zettle_get_product, and there are no exclusions or prerequisites beyond the permission scope.

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