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

Annotations already cover read-only and open-world safety, and the description adds real value on top: pagination, the /dp buyUrl return shape, the affiliate tag per marketplace (sw-fodelsedag-20 / -21), and language/currency behavior. The 'Never an error when missing' note usefully signals a total fallback. It omits rate limits, page-size behavior and ordering of results.

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 with the core identity front-loaded and the marketplace resolution detail after it. 'OpenAPI: getCatalog' is low-value filler, but overall there is little waste.

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 9-parameter, zero-required, no-output-schema listing tool, the description covers return shape and marketplace selection but leaves paging defaults, filter interactions (single giftCategory vs comma-separated giftCategories, occasion) and result ordering undocumented. Adequate, not 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 coverage is 56%, so the description is expected to compensate, and it only partially does: it elaborates marketplace/locale/currency semantics (much of which the marketplace schema description already states) while saying nothing about q, limit, offset, occasion or giftCategory/giftCategories. The affiliate-tag mapping is the only genuinely new parameter detail.

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 first sentence names the resource concretely: a paginated, hand-picked birthday-gift catalog whose results carry /dp buyUrls. That distinguishes it reasonably from a free-text search, but it never names search_gifts or explains how the two differ, so sibling differentiation rests on inference.

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 by 'hand-picked birthday gifts' — an agent can guess this is for browsing a curated list. There is no explicit when-to-use/when-not guidance and no mention of alternatives such as search_gifts or resolve_product, which are the obvious siblings.

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