h3_image_to_video

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

With no annotations, the description fully discloses operational behavior: execution time ('~3-4 min at the defaults on an RTX 4090'), immediate return with a prompt_id, polling recommendation using estimated_seconds, the single-continuous-shot limitation, resolution defaults and trade-offs, frame length constraints, and the sage_attention redundancy caveat. This is exceptional transparency for a complex 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?

The description is longer than typical but every sentence earns its place. It is front-loaded with the core purpose, then delivers practical operational details, performance expectations, and caveats in a structured, scannable format. No redundancy or 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?

For a 15-parameter tool with no output schema, this description is remarkably complete. It covers the execution flow (returns prompt_id, poll job_status), performance, constraints, parameter defaults, and gotchas. The only minor omission is detailed error handling, but the provided context is sufficient for an agent to invoke and monitor the tool correctly.

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%, so the description compensates by explaining the most significant parameters: length (frame count, 24fps, grid snapping, range), width/height (defaults and advice), sage_attention (do not set without list_assets), and first_frame/last_frame (local path or input-folder name). However, several parameters like steps, seed, scheduler, sampler_name, megapixels, shift_audio/video, and filename_prefix are left unexplained, though many are conventional.

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 clearly states a specific action: 'Generate video with synchronized audio from a text prompt, optionally anchored by a first and/or last keyframe (MiniMax-H3 fl2va model)'. It distinguishes between text-to-video and image-anchored modes but does not explicitly differentiate from the sibling tool h3_reference_to_video, which is a similar generation tool.

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?

Provides concrete usage context such as 'With no keyframes this is pure text-to-video' and warns against multi-shot use: 'cannot contain cuts, so for a multi-shot sequence call this once per shot and edit the clips together'. Also advises checking list_assets before setting sage_attention. Does not explicitly name alternative tools, but clear situational guidance is present.

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