Generate motion graphic

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

Despite annotations covering safety (readOnlyHint=false, destructiveHint=false), the description adds rich behavioral disclosure: default transparent WebM output vs opaque MP4, 2–5 minute render time because VideoGen writes animation code then renders, longer for complex prompts, and polling expectations. This is exactly the extra context the annotation set cannot provide.

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?

Front-loads the purpose, then gives use-case, output format, references, timing, and polling guidance in tight sentences. Every sentence earns its place; 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 complex 7-param tool with nested objects, the description covers use case, output format, timing expectations, and polling behavior, and an output schema exists so return values needn't be explained. The few uncovered params are fully documented in the schema, leaving no critical gap for an agent to call it 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 86%, so the schema already documents most parameters (including the transparentBackground default and aspectRatio semantics). The description reinforces transparentBackground and fileIds ('reference media file ids to display or animate') but omits entityIds, subToolModes, and durationSeconds. Baseline 3 is appropriate when the schema does the heavy lifting.

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+resource ('Generate an animated motion graphic video from a text prompt') and immediately distinguishes it from siblings by scoping it to precise text animations (typing effects, kinetic typography, lower thirds) that stock/generated footage can't express. An agent can tell this apart from generate_video_clip or prompt_to_video_clip without opening their schemas.

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?

Gives clear when-to-use guidance ('Best for precise text animations...') and contrasts implicitly against stock/generated footage alternatives. It also adds operational guidance (wait 2–5 minutes, keep polling calmly). It stops short of naming specific sibling tools or explicit when-not-to-use conditions, so not a full 5.

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