set_fade

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

With no annotations provided, the description fully carries the behavioral disclosure burden. It explicitly states that existing keyframes on the property are cleared first, a destructive side effect, and explains the source-time offset issue. These are critical transparency elements that go beyond basic function.

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 three sentences, front-loaded with the primary action. Each sentence earns its place: the first states what it does, the second explains the keyframe clearing rationale, and the third addresses a subtle edge case. No wasted words or redundancy.

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 is remarkably complete for a tool with 3 parameters and no output schema. It covers the operation, the side effect on existing keyframes, and the source-time offset handling. There are no significant gaps in understanding how the tool behaves and how it interacts with clip state.

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%, providing baseline 3. The description adds meaning by connecting fade parameters to opacity/volume and explaining why they work correctly given keyframe clearing and source-time offsets. This enriches understanding beyond the schema's simple descriptions.

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 identifies the tool's function with a specific verb and resource: 'Put a clean fade in and/or out on a clip.' It further specifies the affected properties (Opacity for video, Volume for audio), which distinguishes it from other audio/video adjustment tools like set_audio_level or set_scale.

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 when to use this tool by explaining why it's superior to naive keyframing: it clears existing keyframes and handles source-time offsets. This gives clear context for appropriate use, though it doesn't explicitly name alternatives or state when not to use it.

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