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

No annotations are provided, so the description carries the full behavioral burden. It usefully discloses that this is a multi-stage mutation that produces a new completed media version, but omits whether the operation is long-running/async, whether the original media version is altered, what permissions or credits are required, and how failures mid-pipeline are handled.

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?

A single front-loaded sentence that names the operation first and then the pipeline stages. No filler, no repetition of the tool name.

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?

For a six-parameter mutation pipeline with no annotations and no output schema, the description covers what happens but not how the caller should behave: no async/polling expectations, no indication of what the completed media version returns, and no differentiation from sibling voice/lip-sync tools.

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 six parameters (including voiceId, videoUrl override, and voiceReferenceUrl) are already documented in the schema. The description adds no syntax, format, or dependency guidance (e.g., clone vs. reference mode) beyond that baseline.

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?

States a specific verb+resource ('Run the video voice-change pipeline') and then enumerates the exact pipeline stages, which lets an agent distinguish it from change_audio_track_voice (audio-only) and lip_sync_video_media without opening the schema.

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?

No when-to-use guidance, no prerequisites, and no routing against obvious alternatives such as change_audio_track_voice or lip_sync_video_media. The agent must infer from the name that this operates on a whole video rather than an audio track.

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