grok_generate_video

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

With no annotations, the description carries the full burden and does well: it discloses the experimental/fragile nature (Grok's web UI changes often), the quota cost and daily cap, and the return shape. It omits whether the call blocks, how timeout_s behaves, or failure modes, keeping it below a 5.

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?

Dense and front-loaded: the EXPERIMENTAL warning leads, then capability, then cost/cap caveats, then return format. Nearly every sentence earns its place; minor length comes from the parenthetical file-format note.

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?

Return shape is given despite no output schema, and the cost fragility is covered. However, four of six parameters remain unexplained, which for a tool with this much quota risk is a meaningful gap in what an agent needs before calling.

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% across 6 parameters, so the description must compensate — yet it only explains prompt and image_path (with accepted formats). name, aspect, out_dir, and timeout_s are left entirely undocumented in both schema and description.

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 ('make a Grok Imagine video ... from a prompt'), gives the output duration (~6 s), and describes an optional image-animation mode. An agent can distinguish this from grok_generate_image without opening either 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?

Explicitly flags the tool as EXPERIMENTAL, warns that videos cost much more quota than images, and points to grok_usage / max_videos_per_day for caps. It doesn't say 'prefer grok_generate_image for stills', but the cost comparison effectively routes the agent.

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