Create layer mixer

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

The description adds behavioral context beyond annotations, such as the creation of demo sources when inputs are insufficient and the output being a Null ready for post-processing. It does not contradict the annotations (readOnlyHint false, destructiveHint false, openWorldHint true).

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 concise (three sentences) and front-loaded with the purpose. Every sentence provides essential information without redundancy.

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's complexity, provided annotations, and lack of output schema, the description adequately covers creation of demo sources, blend modes, and output readiness. It lacks details on the exact output structure but is sufficient for an agent to use 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 description clarifies the two modes for the blend parameter, the demo source fallback for inputs, and the crossfade-only condition for expose_controls. With 75% schema coverage, the description adds value beyond the schema, though parent_path lacks elaboration.

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 builds a VJ-style layer mixer combining source TOPs into one output, with specific modes (crossfade and other blends). It distinguishes itself from sibling tools like create_video_player or create_video_synth by focusing on layer mixing.

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 explains that sources are pulled via Select TOPs and demo sources are created when fewer than two inputs are provided. However, it does not explicitly state when to use this tool versus alternatives like create_kaleidoscope or create_glitch, leaving some ambiguity.

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