mux_narration

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

With no annotations, the description carries the full burden. It discloses that video stream is copied (no re-encode) and audio is loudness-normalized, and that ffmpeg is required. However, it does not mention side effects like overwriting files, potential performance impact, or failure modes. This is reasonable but not rich.

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 a single, well-structured sentence that starts with the action and includes key output details and a dependency. Every part adds value, and it is appropriately sized.

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 description covers the core behavior and output format, and the schema is complete. However, it does not mention potential errors, the return value, or what happens if segments overlap or offsets are invalid. Given the complexity of video processing, a bit more context would be helpful.

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 all three parameters (video, output, segments) are already described in the schema. The description adds no additional parameter-level information, so the baseline of 3 applies.

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 function: layering narration segments over a video with precise offsets and producing an .mp4. It names the specific resource (rendered narration segments, recorded video) and the output format. While it doesn't explicitly distinguish from sibling tools like compose_final_video, the specific verb and output details make the purpose clear.

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 this tool is used after rendering narration and on a recorded video, but it gives no explicit guidance on when to use this tool versus alternatives. There is no mention of 'use render_narration first' or 'instead of compose_final_video'. The only prerequisite mentioned is ffmpeg.

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