concat_videos

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

With no annotations, the description carries the full transparency burden. It discloses key behaviors: lossless concatenation, no re-encoding, speed, and input compatibility requirements. This goes beyond a simple 'joins files' statement and informs the agent of critical constraints and expected performance.

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 concise sentences: the first states the core purpose, the second adds behavioral and constraint details. No filler, front-loaded with the verb phrase 'Join multiple video files', and 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 simplicity, full parameter schema coverage, and absence of an output schema, the description sufficiently covers the main behavior, constraints, and output file creation. It could mention error handling for mismatched inputs, but the prerequisite is already stated, making this complete enough for a concatenation tool.

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%, giving a baseline of 3. The description adds semantic value by emphasizing that order matters ('in the order provided') and specifying that inputs must share codec/resolution, which directly relates to the file_paths parameter and potential failure conditions.

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 begins with a specific verb and resource: 'Join multiple video files into a single file in the order provided.' This clearly distinguishes it from sibling tools like trim, split, and convert, which perform different operations on single files or change encoding.

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 useful context by stating 'without re-encoding (lossless, very fast)' and the requirement that inputs share codec and resolution. This implies when to use it (lossless, quick joins) and when not to (if formats differ), though it does not explicitly name alternative tools or state exclusions.

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