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

With no annotations, the description carries the full burden and does so well: it discloses the two return states (valid with signed handoffUrl, invalid with {path, code, message} errors) and the non-obvious side effect that invalid drafts are still persisted so the caller can iterate. It omits permission/auth requirements and any rate or size limits, which keeps it short of a 5.

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 dense sentences, front-loaded with the action and followed immediately by the outcome contract. Every clause carries information (return shape, error structure, persistence behavior, recovery path) with no filler.

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?

There is no output schema, so the description takes on the return-value burden and fully discharges it by describing both status branches and the error object shape. Combined with the 100% schema coverage on inputs, an agent has everything needed to call and handle this tool.

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 documented there, so the baseline is 3. The description restates the DesignDocumentV3 input and confirms templateId/templateVersion are service-set, but adds no format or constraint detail beyond the schema.

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+source ('Create a design draft for a product from a DesignDocumentV3'), and distinguishes itself from the sibling update_design by naming it as the resubmission path. An agent can tell create_design apart from get_design/update_design without opening a 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?

Explicitly routes the agent: fix the returned errors and resubmit 'via update_design', and the productRef must come from list_personalizable_products. It gives clear context for follow-on calls but does not state when the tool should not be used (e.g. editing an existing draft).

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