ffmpeg__split_video

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

With no annotations provided, the description fully discloses behaviors: it states the JSON stdout output structure, fallback to FFMPEG_OUTPUT_DIR or SHELL_AS_MCP_OUTPUT_DIR, and the re-encoding default with its keyframe misalignment consequence. This is comprehensive.

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 well-structured: a one-sentence purpose, a remarks block for shared behavior, then per-parameter docs. Every line adds value with no wasted words or repetition.

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 six parameters and no output schema, the description covers all inputs, the output JSON shape, environment fallbacks, and behavioral nuances. An agent would have everything needed to invoke and understand the result.

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 schema has 0% description coverage, but the @param lines explain every parameter, including examples (split_points), defaults (output_prefix, reencode), and fallback logic (output_dir). This fully compensates for the schema's silence.

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 'Split a single video into multiple segments at specified timestamps,' using a specific verb and resource while scoping the operation. This clearly distinguishes it from sibling tools like concat_clips or extract_frames.

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 clear context on how to use the tool, including the required parameters and flexible timestamp formats. It explains the reencode default and its trade-off, but does not explicitly name alternatives or when-not-to-use conditions.

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