animate_character

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

No annotations are provided, so the description carries the full burden. It reveals that the tool uses the character's existing size and requires a character_id from specific creation tools, but omits behavioral traits such as return value (likely a job ID), async nature, error handling, or authentication requirements. Significant gaps remain.

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 sentences long, front-loaded with purpose, and contains no wasted words. It efficiently communicates the core function, prerequisite, and an alternative.

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?

Despite having 14 parameters and no output schema, the description fails to explain what the tool returns (likely a job ID) or that it may be asynchronous. It does not address the many optional parameters for customization (e.g., detail, outline, shading). Incomplete for a complex tool with many siblings.

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 100% with all parameters described. The description adds minimal value by listing example template names (walk, run, attack) but does not elaborate on optional parameters like detail, outline, or directions. Baseline 3 is appropriate as the schema already documents parameters well.

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 it animates a saved character by ID using a preset animation template, providing a specific verb and resource. It distinguishes itself from animate_with_text_v2 by noting the prerequisite of a saved character, but does not differentiate from other animate siblings like animate_with_skeleton or animate_with_text_v3.

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 description explicitly states when to use the tool (saved character with preset template) and when not to (only image → use animate_with_text_v2). This provides clear context and an alternative, though it does not cover all possible alternatives among siblings.

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