Join videos

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

With no annotations, the description discloses a key behavioral trait: clips are normalized (scaled/padded to the first clip's resolution and frame rate) to handle mixed sources. It also mentions hard cuts or crossfade, covering the primary behavioral options. It doesn't mention audio handling or error cases, but the core behavior is well disclosed.

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 compact sentences: the first states the core purpose, the second adds an essential behavioral detail. No fluff or redundancy; front-loaded for quick comprehension.

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 three-parameter tool with no output schema, the description adequately explains the main operation and the normalization behavior that affects mixed-resolution inputs. It doesn't need to explain return values, and the schema covers default output location. Slight gap: no mention of audio handling, but not critical.

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% and each parameter has a clear description. The tool description adds no parameter-specific meaning beyond the schema; the normalization note is about processing, not parameter semantics. Baseline 3 applies.

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 action: 'Concatenate two or more videos into one file, in the order given'. It also specifies the crossfade option and order, distinguishing it from sibling tools like stack_videos or trim_video.

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 provides a clear use case: joining multiple video clips sequentially. It doesn't explicitly mention alternative tools, but the context is unambiguous, and no exclusions are needed beyond the implied 'for concatenation'.

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