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

No annotations exist, so the description carries the full burden. It does disclose that the invocation queues an asynchronous V3 job rather than producing a result inline, which is genuinely useful. It omits permissions/auth needs, cost, expected duration, and how to poll the queued job.

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?

Two short sentences, front-loaded with the action and followed by the execution model. Every clause carries information; the only minor deduction is that the second sentence is compressed to the point of jargon ('V3 job', 'MediaDocV2') without unpacking it.

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 6-parameter mutation-style tool with a nested free-form extraParams object and no output schema, the description should say what the call returns (e.g., a job or media ID) and how the queued job is tracked. It covers the core action but leaves result handling and the extraParams escape hatch unexplained.

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 the schema already explains mediaId, modelId, audioUrl, videoUrl, extraParams, and workspaceId. The description only reinforces the media/audio relationship and adds nothing about the videoUrl override or extraParams passthrough semantics, so the baseline 3 is appropriate.

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 lip sync on a video media item using a supplied audio URL.' It also identifies the mechanics ('Queues the V3 job against the existing MediaDocV2'), which separates it from generic voice/edit tools. It does not explicitly name a sibling it is not, so it falls short of 5.

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?

There is no when-to-use guidance and no mention of alternatives such as change_video_voice or generate_video_audio, which are the closest siblings an agent would weigh against this. 'Against the existing MediaDocV2' implies a precondition but never states it as a rule.

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