Generate video

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

With no annotations provided, the description carries the full burden and does disclose the most decision-critical behavior: that it SPENDS CREDITS, that Flow's quote is gated by max_credits, and that dry_run returns only the quote. It leaves the async/result-retrieval behavior unstated, so it is strong but not complete.

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 dense sentences, front-loaded with the purpose and ingredient behavior before model selection and the credit warning. Nearly every clause earns its place, though the sentence structure runs long.

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 14-parameter mutation tool with no annotations and no output schema, the description covers the highest-stakes gaps (credit spend, quote gating, dry_run, ingredient semantics, model selection). It omits how results are retrieved or polled, which is a meaningful gap for a video generation tool but not fatal.

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 coverage is 71%, and the description adds cross-parameter meaning beyond the schema: character_ids/image_ids acting as 'ingredients' that preserve consistency, the model_key-vs-family/duration_sec/resolution alternative, and Omni's 360p/720p and 4-10s constraints. This exceeds the baseline for a mostly-documented schema.

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 ('Generate video clips through Flow's composer') and clarifies the ingredient mechanism, so the agent can tell it produces video rather than images. It does not explicitly differentiate from siblings like flow_edit_video or flow_generate_image by name, so it lands just below the top band.

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?

Usage is implied rather than stated: it explains model selection via model_key or family+duration_sec+resolution and when to set dry_run, but never says when to prefer this tool over alternatives such as flow_edit_video or flow_generate_image. There are no explicit exclusions.

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