aseprite_new_spriteCreate a new sprite with specified dimensions, color mode, and optional background. Sets it as the active document and returns its status.
Creates a new sprite and makes it active. Returns the sprite status.
| Name | Required | Description | Default |
|---|---|---|---|
| width | Yes | ||
| height | Yes | ||
| colorMode | No | rgb | |
| background | No | Optional: fill the canvas with this color |
Changes observed during successful MCP inspections.
v0.6.0Input schema / properties / background / patternRemoved value: -"^#?([0-9a-fA-F]{3}|[0-9a-fA-F]{4}|[0-9a-fA-F]{6}|[0-9a-fA-F]{8})$"Input schema / properties / height / typePrevious value: -"integer"New value: +"number"Input schema / properties / width / typePrevious value: -"integer"New value: +"number"v0.2.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden of behavioral disclosure. It mentions 'makes it active' and 'returns the sprite status' but omits crucial context such as what happens to the current sprite, whether the operation is reversible, or any side effects. The description is too thin for a creation 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 two sentences with no wasted words. The core action is front-loaded, and it is appropriately brief for a simple creation tool.
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 no output schema and no annotations, the description is incomplete. It does not specify what 'sprite status' includes, the format of the background color, or any constraints beyond the schema. An agent cannot fully predict the tool's behavior from this description.
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 only 25% (only background has a description). The description adds no additional meaning for width, height, or colorMode, leaving the agent to infer their purpose. It does not compensate for the low schema coverage 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 'creates', the resource 'new sprite', and the side effect 'makes it active', which distinguishes it from sibling tools like open or clear. It is specific and unambiguous.
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 this is the tool for creating a new sprite, but it does not explicitly state when to use it versus alternatives, nor does it provide any exclusions or prerequisites. It relies on the agent to infer from the sibling names.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.