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

Annotations already declare destructiveHint=true, idempotentHint=false, and openWorldHint=true, so the safety profile is covered. The description adds useful behavioral context beyond annotations: model capability gating, an instruction to select an alpha-capable output format, and the fact that the call returns a tracked task and playable result.

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 sentences, front-loaded with the operation and condition, then prerequisites, then return behavior. Each sentence earns its place and no filler is present.

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 complex 21-parameter tool with nested objects and an output schema, the description orients the agent on model dependency, output format selection, and async return behavior. It omits sibling differentiation and does not mention idempotency or cost controls, but those are largely covered by schema and annotations.

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 81%, so the schema already documents most parameters. The description adds a small amount of meaning for outputFormat and modelSettings by noting alpha-capable output, but it does not provide syntax or constraints beyond the schema for the 21 parameters.

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 description states a specific verb and resource ('Remove a video background') and adds a clear capability condition ('when an active catalog model supports remove_background and video input'). However, it does not distinguish this tool from the sibling remove_video_background_media, so an agent must infer the difference from names alone.

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?

It gives clear context for use: the selected model must support remove_background and video input, and get_model_catalog should be used to choose a supported model and settings. It stops short of explicitly stating when to prefer this over remove_video_background_media or remove_image_background.

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