Render a launch film

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

Beyond the annotations (which only mark it non-read-only, non-destructive, non-idempotent), the description discloses that rendering happens locally via Chrome and ffmpeg, writes output adjacent to the input, and takes a few minutes. The duration warning is the key behavioral signal an agent needs to avoid an impatient retry.

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 short sentences, front-loaded with the core action and outcome before the sequencing advice and the duration warning. The '(launch-film 0.2.0, on this machine.)' trailer repeats locality already stated and is minor 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?

An output schema exists, so return values including job_id need no explanation here. Inputs, prerequisites, runtime cost, and locality are all covered; only the interaction between wait_seconds timeout and job_id polling is left to the schema.

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%, with jobs, keep, and wait_seconds all documented in-schema, so baseline is 3. The description only adds the output-location detail ('next to it') for the film parameter and nothing further about jobs or keep.

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 both endpoints: it renders a film.json into a film.mp4 placed next to it, using Chrome and ffmpeg locally. That distinguishes it from the sibling authoring tools (plan_launch_film, make_launch_film) that produce the input rather than the finished video.

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 says to use it after plan_launch_film or after editing the film.json from make_launch_film, which gives a clear prerequisite sequence. It does not name alternatives such as wait_for_job/cancel_job, but the wait_seconds schema text covers the follow-up path for long renders.

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