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

Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, so safety is covered. The description adds real value beyond them: the required OAuth scope (READ:PRODUCT) and the concrete endpoint path, which tells an agent this is a plain network-backed read against the organization's own product set.

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 short sentences: the first front-loads what the tool returns, the second packs the auth requirement and endpoint. No filler, no repetition of the title.

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?

For a one-parameter read with annotations covering the safety profile, nothing needed to invoke it correctly is missing: the identifier, the auth prerequisite, and the shape of the returned record are all stated. No output schema exists, and the description compensates by listing the returned facets.

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%, so the single product_uuid parameter is already documented in the schema, including its UUID pattern. The description only restates that the lookup is by UUID, adding no format or sourcing guidance beyond the structured field.

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+resource ('One product by UUID') and enumerates exactly what comes back (variants, prices, VAT, category, images, online-store data). This clearly separates it from zettle_list_products, which returns many, without the agent needing to open either 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?

The 'by UUID' framing and the required READ:PRODUCT scope make the appropriate context clear, and the singular 'One product' implies listing should go through the list sibling. It stops short of naming an explicit alternative or stating what to do when the UUID is unknown.

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