Fill a contiguous pixel area at specified coordinates on a named layer and animation frame. Applies a color to enclosed regions for pixel art creation.
Fill a contiguous area on a named layer and animation frame.
| Name | Required | Description | Default |
|---|---|---|---|
| x | Yes | ||
| y | Yes | ||
| color | No | #000000 | |
| filename | Yes | ||
| layer_name | Yes | ||
| frame_index | Yes | ||
| create_if_missing | No |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden of disclosing behavior. It only states 'fill a contiguous area' without explaining that it modifies pixels, how contiguity is determined, whether it respects color tolerance, or that it can create layers via the create_if_missing parameter. Side effects are completely undisclosed.
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 concise sentence with no redundancy, and it front-loads the action. However, it is under-specified rather than appropriately concise, as it omits critical details that should be included.
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 tool with seven parameters, five required, and no annotations or output schema, the description is severely inadequate. An agent would not know what the parameters mean, how the fill operation behaves, or what side effects to expect, making it impossible to call correctly without external knowledge.
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?
The description does not explain any of the seven parameters. With schema description coverage at 0%, the description must compensate by clarifying the meaning of x, y, color, create_if_missing, etc., but it offers no parameter information at all.
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 verb (fill), the target (contiguous area on a named layer and animation frame), and implies a specific starting point via the '_at' suffix and required x/y params. It distinguishes from siblings like fill_area and draw_rectangle, though it doesn't explicitly mention the coordinate-based nature.
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?
There is no guidance on when to use this tool versus alternatives such as fill_area or draw_rectangle. The description provides no context for selecting it over other drawing tools, and no exclusions or preconditions are mentioned.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.