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

Annotations mark this as a non-read-only, non-destructive, closed-world write, but they say nothing about cost or side effects. The description adds two pieces of real value the annotations cannot: the operation consumes credits, and the result surfaces in ClipFlux Studio for review and export. It also implies a long-running async job by directing the agent to get_video for progress, though it never says the call returns before rendering finishes.

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 sentences, front-loaded with the action and its prerequisites, with no filler. The conversational framing ('once the user is happy', 'for a last look') is slightly wordy but carries genuine workflow meaning.

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 one-parameter generation tool with no output schema, the description covers the essential unknowns: cost, what the pipeline produces, and where the user reviews the result. The main omission is that it never states whether the call blocks or returns immediately, which matters for a job that 'draws every picture' and 'records the narration'.

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?

Only one parameter exists and the schema already documents it at 100% coverage, including the exact source tools for the id. The description adds no further meaning about the id, so this sits at the baseline where the schema does all the work.

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 uses a specific verb ('Makes a draft') and then enumerates the concrete sub-steps: draws every picture, records the narration, adds the captions. That is far more informative than the title. It stops short of explicitly distinguishing itself from close siblings like draft_video or edit_video, which an agent must infer from 'once the user is happy with the script'.

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 a clear precondition for invocation ('once the user is happy with the script') and points at get_video for progress, which routes the agent correctly on the follow-up. It does not state when to use edit_video or redo_scene instead, so the exclusion side is left implicit.

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