trim_and_concat_operation

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

With no annotations provided, the description carries the full burden. It discloses key behavioral traits: it outputs a video file path on success or None on error, and mentions normalization and portrait orientation constraints. However, it lacks details on permissions, rate limits, file format specifics, or what constitutes an error. The description adds value but doesn't fully compensate for the absence of annotations.

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 appropriately sized and well-structured with clear sections for Args and Returns. Every sentence adds value: the first states the purpose, the Args section details parameters, and Returns explains outcomes. It could be slightly more concise by integrating the portrait orientation note into the purpose statement, but overall it's efficient.

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 5 parameters with 0% schema coverage and no annotations, the description does a good job explaining inputs, outputs, and constraints. The output schema is present (Returns section), so return values are covered. It addresses the core functionality but could improve by mentioning error conditions or format normalization details to reach full completeness.

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 0%, so the description must compensate. It provides detailed semantics for all 5 parameters: 'inputs' structure with path and optional time ranges, 'width' and 'height' for scaling, and 'x' and 'y' for overlay positioning. Default values are mentioned for x and y. This adds substantial meaning beyond the bare schema, though it doesn't cover all possible edge cases.

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 specific action: 'Trim and concatenate multiple videos' with additional constraints 'portrait orientation, normalize format'. This distinguishes it from siblings like 'concat_clips_with_transition' (which adds transitions) and 'clip_video' (which only trims single videos). The verb+resource+scope combination is precise and differentiated.

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 implies usage for portrait-oriented video concatenation with trimming, but provides no explicit guidance on when to choose this tool over alternatives like 'concat_clips_with_transition' or 'get_normalized_clips'. It mentions 'portrait orientation' as a constraint, which helps narrow the context, but lacks clear exclusions or comparison to sibling tools.

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