luma_extend_video

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

No annotations are provided, so the description carries full burden. It explains that the tool extends the video by adding content after the original ends and returns a task ID. However, it does not disclose potential side effects, authorization needs, or constraints like video length limits, leaving some behavioral aspects unclear.

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 well-structured with a clear purpose statement, bullet points for usage, and a returns line. Every sentence adds value, and there is no redundant or overly verbose content.

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 3 parameters with full schema coverage, existence of an output schema (implied), and sibling tools, the description provides a solid overview of the tool's purpose and inputs. However, it omits prerequisites (e.g., that the video must be from Luma generation) and error conditions, leaving minor gaps.

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%, so baseline is 3. The description does not add significant meaning beyond the schema; it repeats similar phrasing for prompt. No additional parameter semantics are introduced.

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 tool's purpose: 'Extend an existing video with additional content.' It specifies the verb 'extend' and the resource 'existing video.' The bullet points for when to use it help distinguish it from siblings like generating a new video or extending from a URL.

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 includes a 'Use this when' section with three bullet points (e.g., 'A generated video is too short'), providing clear context. It does not explicitly mention when not to use or alternatives, but the listed scenarios are helpful guidance.

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