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

Annotations only declare readOnlyHint=false and openWorldHint=true, so the description adds real value: it discloses the return payload (id, editToken, ownerUrl, shopUrl) and the non-obvious side effect that each itemQueries entry is searched and added as a kit item. It omits failure behavior, whether creation is idempotent, and what editToken grants.

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?

Front-loaded and short, but the return fields are listed twice ('return shopUrl (share link) + ownerUrl' then 'Returns id, editToken, ownerUrl, shopUrl'), and the trailing 'OpenAPI: agentCreateAndFill' is internal noise that doesn't help an agent decide or invoke.

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 mutating, open-world tool with no output schema, the description covers the outputs and required params but leaves half the inputs unexplained and says nothing about what editToken is for or what happens when the call fails. Adequate but with clear gaps.

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?

With only 33% schema description coverage, the description must compensate; it partially does by mapping itemAsins / itemKeywords / itemQueries to fill behavior and flagging marketplace + locale as required. The other four parameters (moveType, roomFocus, budgetBand, householdName) are left entirely to their bare names.

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?

Specific verb and resource: 'create a curated housewarming / moving in gift wishlist' plus a one-shot fill, and it names the return artifacts (shopUrl, ownerUrl). It also implicitly contrasts with the create_kit + add_kit_item path ('Preferred agent path: create a kit and add ASINs...'), though it never names those sibling tools 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' clearly signals this is the default route over composing create_kit + add_kit_item, and 'ALWAYS pass marketplace + locale' is a concrete invocation directive. It stops short of stating when NOT to use it (e.g. adding items to an existing kit).

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