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

With no annotations, the description carries the full burden, yet it only implies single-image output and mentions 'commercial-grade' (a usage-rights hint). It omits cost, latency, moderation/content-policy behavior, output format or size, and auth requirements for a paid generation endpoint.

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?

A single front-loaded sentence with no filler; the key constraints (one image, optional references) are stated up front and nothing is wasted.

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?

The existence of an output schema excuses it from describing return values, but for a generation tool with a nested payload and an opaque 'reference_image_keys' array, the agent is left without guidance on obtaining keys, aspect-ratio tradeoffs, or operational constraints. The definition is too thin for the tool's complexity.

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 0%, so parameter meaning must come from the description. It clarifies that the prompt is the input and that reference images are optional, but never mentions aspect_ratio or explains what a 'reference_image_key' is or how to obtain one. Partial compensation only.

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 and resource ('Generate ... image') plus the distinguishing scope modifier 'one' and 'commercial-grade', which sets it apart from the sibling video-generation and from any batch tool. It does not name an alternative explicitly, but the purpose is unambiguous without opening the 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?

There is no when-to-use guidance, no prerequisite (e.g., where reference_image_keys come from), and no exclusion criteria or named alternative. The agent can infer image generation from the name, but the description adds no routing information.

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