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

Annotations only say it writes and is open-world; the description adds real behavior: the exact return fields (id, editToken, ownerUrl, shopUrl) and the marketplace-dependent outcome (curated real /dp ASINs on amazon.se/amazon.com vs. romantic search deep-links elsewhere). Reversibility and rate/size limits are not covered.

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?

Four short sentences, front-loaded with the purpose and the routing hint, then returns, then required inputs. The trailing 'OpenAPI: agentCreateAndFill' reference is marginal but harmless.

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 10-parameter composite write tool with no output schema, the description covers returns and marketplace behavior well but leaves the majority of optional parameters (occasion, styleTags, budgetBand, relationship, recipientName) unexplained, so an agent cannot tell how they affect the created list.

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 only 30%, so the description must compensate but does not. It mentions marketplace, locale, and the ASINs/keywords/queries triplet, but occasion, styleTags, budgetBand, relationship, and recipientName are explained nowhere — and it is unclear whether those shape the fill or are just metadata.

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 compound verb and resource: create a gift wishlist and fill it with ASINs/keywords/search queries in one call. The 'one-shot' framing implicitly distinguishes it from the create_wishlist + add_wishlist_item pair, though it never names those siblings explicitly.

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?

'Preferred agent path for list-building' gives a clear selection signal against the sibling create_wishlist/add_wishlist_item workflow. It stops short of stating when NOT to use this composite path (e.g., adding to an existing list), so it is not a full 5.

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