create_omni_character

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

No annotations are provided, so the description bears full burden. It mentions the combination of image and optional voice and the return of a characterId, but does not disclose side effects, error handling, limitations on image URLs, or permission requirements.

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 very concise, with three short, front-loaded sentences. No wasted words, but could be slightly more structured to separate purpose, behavior, and output.

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?

Given the tool has 4 parameters (2 required) and no output schema, the description is incomplete. It does not explain constraints on image URLs, how characterId is formatted, or how this tool fits into the video generation workflow.

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 100%, providing clear parameter descriptions. The tool description adds 'Combines image + optional voice' and 'Returns characterId', slightly extending schema info but not substantially.

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 the verb ('Create'), the resource ('reusable visual character for Gemini Omni video generation'), and distinguishes from siblings like 'create_omni_voice' by specifying that it combines image with optional voice.

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 implies usage for creating characters but does not explicitly state when to use this tool versus alternatives (e.g., generate_video) or provide prerequisites. Lack of exclusions limits guidance.

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