animate_scene

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

With no annotations, the description carries the transparency burden. It discloses that the tool generates characters, places a background, animates along paths, and returns PNG frames. However, it doesn't state whether the tool mutates an existing canvas/workspace, has side effects on prior state, or requires specific prerequisites before calling.

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 three short sentences, front-loaded with the core purpose. Every sentence adds information about capabilities or output; no redundant phrasing.

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?

The tool is complex (nested actors, background, 8 params) and lacks an output schema, yet the description adequately conveys the main output ('multiple PNG frames') and high-level behavior. It doesn't detail frame sequencing or default timing, but the schema covers those parameters; the description is sufficient for an agent to select and invoke 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?

The schema covers all 8 parameters with descriptions (100% coverage), so the baseline is 3. The description adds a meaningful connection by saying 'animate them along paths,' which maps to the actors' from/to coordinates, providing semantic glue not explicit in the 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?

The description clearly states 'Create a full animated scene in one call,' names the key actions (generate characters, place on background, animate along paths), and notes it returns multiple PNG frames. This distinguishes it from sibling tools like 'pixel' or 'rectangle' which handle individual drawing primitives.

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?

The phrase 'full animated scene in one call' signals this is for high-level scene creation, implying a contrast with lower-level sibling tools, but it does not explicitly name alternatives or state when not to use it. There is no mention of using 'character' for standalone sprites or 'animate' for existing assets.

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