tween_cel_positions

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, and it falls short. It does not reveal what happens to existing cels, how missing cels are handled, whether create_missing_cels or source_frame_index affect behavior, or whether positions are overwritten or interpolated into new cels. For a mutating tool with 10 parameters, this is a significant transparency gap.

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 a single, tight sentence with no filler or repetition. It is front-loaded with the core action and scope, making it easy to scan. However, it is arguably too terse for a tool with this many parameters, so it sacrifices informative content for brevity.

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 the tool's complexity—10 parameters, 8 required, no annotations, no output schema, and 0% schema description coverage—the one-sentence description is grossly insufficient. It omits all edge-case behavior, optional parameter effects, prerequisites, and any sense of what the operation does to the sprite's frame sequence. An agent cannot confidently invoke this tool correctly with only the provided information.

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 explain parameter meanings, but it only mentions 'positions' and 'frame range' at a high level. It does not map start_x/start_y/end_x/end_y to the start and end frames, nor does it clarify the purpose of source_frame_index or create_missing_cels. The description adds minimal value beyond the parameter names themselves.

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 uses a specific verb ('Tween') with a clear resource ('cel positions') and scope ('across a frame range'). The qualifier 'linearly' explicitly differentiates it from the sibling tool tween_cel_positions_eased, which introduces easing. This is concrete and unambiguous enough for an agent to understand what the tool does.

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 the tool is for linear motion over a frame range, which suggests it is the right choice when no easing is needed. However, it does not explicitly state when to use it over the many related sibling tools (e.g., tween_cel_positions_eased, set_cel_position, offset_cel_positions), nor does it provide exclusions or alternative guidance. The context is present but largely implicit.

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