set_clip_features

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

The description adds substantial behavior beyond the annotations: features merge per group for transform/style/keyframes while others replace, passing null removes a group, keyframes use clip-relative seconds with linear interpolation, and circle width defaults compensate aspect ratio. It also discloses the 'new revision' behavior, which is not visible from the schema or 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 dense but well-structured: a one-sentence summary is front-loaded, followed by semicolon-separated group specifications. Every section adds necessary detail, though the volume of technical field lists makes it long and heavy to parse.

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?

For a complex nested-object tool with no output schema and sparse annotations, the description covers the main content model, merge/replace semantics, removal via null, resource resolution, and keyframe interpolation. It is incomplete only in that it omits explanations of dry_run/include_plan and does not specify what the tool returns or how a new revision is named.

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 thoroughly documents the 'features' object's structure, field names, units, defaults, and nesting. However, it does not explain top-level parameters like dry_run, include_plan, name, new_name, or clip_ids, leaving some parameter semantics to the agent to guess.

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 first sentence states a specific action ('Apply advanced controls') on a specific resource ('selected clips') with an important scope qualifier ('in a new revision'). The detailed group list (transform, crop, text_style, keyframes, etc.) clarifies what 'advanced controls' means and distinguishes this from sibling tools like apply_motion_preset or style_subtitles.

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 by enumerating the supported feature groups and gives one prerequisite ('Resolve downloaded native resources first'), but it does not explicitly state when to prefer this tool over alternatives like apply_motion_preset or batch_edit. There are no exclusions or 'instead of' notes, leaving the choice of tool partly to inference.

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