kling_lip_sync

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

With no annotations, the description carries the behavioral burden. It transparently explains the transformation ('replaces the speaker's lip movements'), the mode behavior (text2video generates audio via TTS), and the return shape (Task ID and lip-sync video information). It does not explicitly describe async behavior or error conditions, but the return of a Task ID implies polling/callback, and the callback_url parameter is present in the schema.

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 compact and front-loaded with the core action, followed by a brief explanation, a 'Use this when' bulleted list, and a Returns line. Every sentence adds value and there is no fluff or 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?

For a tool with 11 parameters and an output schema, the description covers the essential context: purpose, input types (URL, task ID, audio, text), modes, use cases, and return. It omits explicit async execution notes and prerequisites (e.g., video must contain a face), but given the schema richness and output schema, this is adequate and above minimal viability.

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 coverage is 100%, with every parameter having a description. The description adds only high-level context (e.g., 'takes an existing video by URL or task ID') that maps directly to video_url/video_id and audio_url/audio_file. It does not add meaning beyond the schema's parameter descriptions, earning the baseline of 3.

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 opens with a specific verb and resource: 'Synchronize lip movements in a video to match a given audio track or text.' It clearly distinguishes the tool from siblings like kling_generate_video and kling_talking_photo by explaining it replaces lips in an existing video. The two modes (audio2video and text2video) are explicitly described.

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 'Use this when' section explicitly lists three concrete scenarios (dubbing, replacing audio, talking-head from text), providing clear context for when to use the tool. However, it does not mention when not to use it or name alternative sibling tools, so it stops short of a full 5.

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