video2video

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

There are no annotations, so the description carries the full burden. It does disclose the core operation and optional behaviors: background music, voiceover, head/tail fixation, cover image, and volume control. But it does not disclose whether the operation is asynchronous, what the output/return value is, or any constraints on video count, duration, or format — leaving significant behavioral uncertainty.

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-loads the main purpose, then enumerates supported features in the following sentences. It has minor redundancy — '合成新的视频' appears twice — but otherwise every sentence adds relevant capability information and all parameter categories are represented.

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 9-parameter tool with no annotations and no output schema, the description covers all major features and parameter roles. However, it omits important operational context such as the expected return value, synchronous versus asynchronous processing, input size limits, and supported media formats. The rich schema descriptions compensate partially, making it adequate but not fully complete.

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%, with each of the 9 parameters already having its own description, so the baseline is 3. The tool description restates some parameter roles (e.g., optional background music, voiceover volume, cover image) but adds little new meaning beyond the schema — no URL format details, volume ranges, or conditional requirements.

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 states a specific verb and resource: '将一个或多个视频素材合成一个视频' — merging video materials into a new video. It clearly differentiates itself from sibling tools like imgs2video (images-to-video) and videoCutRandom by centering on video materials as input and listing concrete capabilities such as fixed head/tail videos, cover image, and volume control.

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 intended use is implied through phrases like '通过视频素材合成新的视频' and '将一个或多个视频素材合成一个视频'. However, there is no explicit guidance on when to choose this tool over siblings, nor any exclusions such as 'use imgs2video when the source is images' or 'use videoCutRandom for random cutting'.

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