trim_video

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

With no annotations, the description carries the full burden. It discloses key behaviors like snap-to-keyframe and stream copy (no re-encode), which are valuable. However, it omits crucial output behavior—whether it overwrites the file, creates a new file, or requires an output path—which is essential for an agent to safely invoke the tool.

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?

Three sentences, each contributing unique value: the core action, timestamp format rules, and keyframe behavior. No redundancy, front-loaded with the primary function, 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?

The tool is simple and the schema covers all parameters, but the description omits details about the output—whether a new file is created, if it overwrites, or if an output path is needed. For an agent to call this correctly, that output behavior is a critical missing piece, so the description is 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 coverage is 100%, so baseline is 3. The description adds explicit timestamp format specifications (seconds, MM:SS, HH:MM:SS) and explains how keyframe snapping affects the interpretation of timestamps, which goes beyond the schema's examples and enriches parameter understanding.

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 action ('Cut a segment out of a video') with a clear temporal scope (start to end), which distinctly separates it from spatial operations like crop_video and concatenation tools like concat_videos. The verb and resource are explicit and unambiguous.

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 guidance on timestamp formats (seconds, MM:SS, HH:MM:SS) but does not explicitly state when to use this tool versus alternatives such as crop_video or extract_frame. The usage context is implied by the operation itself, but no exclusions or alternatives are mentioned.

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