Join videos

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

No annotations are provided, so the description carries the burden. It discloses key behaviors: clips are normalized to the first clip's resolution/frame rate, and crossfade or hard cuts are applied. It does not mention audio handling or whether inputs are modified, but the most relevant behaviors are covered.

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 two sentences long, front-loaded with the core action, and includes a useful detail about normalization without any fluff. Every sentence earns its place.

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?

Given the tool's moderate complexity, no output schema, and no annotations, the description is reasonably complete. It explains the concatenation behavior and normalization, which are the most important aspects. It doesn't mention potential side effects like overwriting output, but the schema's output_path description covers where the result goes.

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?

The input schema covers 100% of parameters with clear descriptions. The description adds only the normalization context, which is not directly tied to a specific parameter. Baseline of 3 is appropriate since the schema already documents parameter meanings.

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 concatenates two or more videos into one file in the order given, with hard cuts or crossfade. It uses a specific verb and resource, and the normalization detail distinguishes it from video stacking or editing tools like stack_videos.

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 when to use the tool (joining videos sequentially) and mentions the order of inputs, but it does not explicitly contrast with alternatives like stack_videos or picture_in_picture. Clear context is provided, but no explicit exclusions or alternative tool names are given.

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