Trim a clip

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

This text carries the full burden since annotations are minimal. It discloses critical behaviors: stream-copy snaps to keyframes, reencode is frame-accurate, and the job reports actual output duration. This goes beyond what annotations provide and helps set expectations for job results.

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 short paragraphs: the first states the core purpose, the second explains the key behavioral nuances. Every sentence earns its place with no fluff, front-loading the most important information.

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 description covers the essential context for a trim operation: what it does, the key behavioral difference between copy and reencode, and how to verify results. Given the rich input schema and presence of an output schema, this is sufficient for correct use.

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 83%, so most parameters are already well documented. The description adds meaningful semantics beyond the schema, particularly for the 'mode' parameter (explaining keyframe snapping) and the 'output_path' behavior (job workspace path). This elevates it above the baseline.

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 'Cut a segment out of a video or audio file.' This is a specific verb ('cut') and resource ('video or audio file') that clearly distinguishes it from siblings like concat or convert_format. The additional detail about stream-copy versus reencode further clarifies its purpose.

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 when to use stream-copy vs mode='reencode', explaining the tradeoff between speed and frame accuracy. It does not explicitly name sibling tools or state when not to use this tool, but the context is clear enough for an agent to decide appropriately.

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