tween_cel_opacity_eased

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

With no annotations, the description carries the full burden of behavioral disclosure. It states that a tween is performed with easing, but does not disclose whether existing cels are modified, whether missing cels are created (create_missing_cels), what source_frame_index does, whether the source cel is preserved, or what happens at frame boundaries. This is substantial missing behavior for a mutating animation 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?

The description is one short, front-loaded sentence with no filler words. It is efficient, though arguably too terse for a nine-parameter tool. The conciseness itself is not the problem; the lack of compensating detail is.

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 nine parameters, no annotations, no output schema, and 0% schema description coverage, this description is far too incomplete. An agent cannot determine what source_frame_index means, whether cels are created, how easing curves differ, or what the tool returns. It needs substantial elaboration to be reliably invokable.

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 for the nine parameters. It vaguely maps to opacity, frames, and easing, but it does not explain filename, layer_name, source_frame_index, create_missing_cels, or the meaning of each easing option. The '0 to 255' phrase adds some context about opacity values, but it does not clarify start_opacity and end_opacity are independent configurable values.

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 identifies a specific operation ('tween'), a specific resource ('cel opacity'), and the animation context ('across frames with easing'). This distinguishes it from siblings like tween_cel_positions_eased and tween_cel_scale_eased. However, the phrase 'from 0 to 255' is ambiguous: it could mean the allowed opacity range or fixed start/end values, which the start_opacity and end_opacity parameters do not imply.

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?

No guidance is given for when to use this tool versus alternatives such as set_cel_opacity, tween_cel_positions, or oscillate_cel_positions. There are no stated prerequisites, exclusions, or side-by-side comparisons with sibling tools.

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