Generate a video

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

Beyond the annotations, the description reveals that credits are only spent when auto_confirm=true, that the preparation phase sends nothing, and that resume skips the composer to wait for or download an in-flight job. These are important side-effect and recovery behaviors the agent needs to know before invoking the tool.

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?

Three sentences, each earning its place: the core action, the credit-safe preparation rule, and the resume recovery path. There is no filler, tautology, or redundant restatement of the tool name.

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 an 11-parameter tool with an output schema and side effects, the description covers the full lifecycle: prepare, confirm/send, wait/download, and resume after failure. Sibling tools like flow_status and flow_media_download handle adjacent concerns, so nothing critical is missing.

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 73%, so the schema already documents most parameters. The description adds meaningful scenario-level meaning to auto_confirm, resume, prompt, and reference_images, e.g. 'nothing is sent' at auto_confirm=false and 'skips the composer' for resume. This compensates well for parameters whose semantics are only partially covered.

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 opens with 'Generate one video through the Flow agent composer and download it,' a specific verb-resource-action combination that clearly distinguishes it from siblings like flow_generate_image. It also explains the two-phase generation flow, which further clarifies what the tool accomplishes.

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?

The description explicitly instructs the agent to call with auto_confirm=false first to prepare and verify, then proceed to auto_confirm=true to spend credits and send. It also defines resume=true for recovering in-flight generations after a crash or timeout, giving clear when-to-use and sequencing guidance.

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