pixel_outline_sprite

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

The description adds context beyond annotations: it explains that the outline occupies transparent pixels without altering the art itself, describes the return format (JSON with canvas, color, pixels_outlined; image on preview=true), and mentions error handling. Annotations indicate destructive and idempotent hints, which the description supports.

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 well-structured and concise: it starts with the main action, explains a key nuance (canvas edge), specifies return format, and ends with error handling. Every sentence contributes meaningful information.

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 (outlining with options for corners and preview), the description covers the core behavior, an important edge case, return values, and error handling. It lacks detail on idempotency or multi-call behavior but is otherwise complete for typical use.

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 parameter meaning. However, the description does not address individual parameters; it only mentions return fields. The input schema already provides basic descriptions for each parameter, but the tool description adds no extra value for parameter semantics.

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 verb and resource: 'Draw a 1px outline around all opaque art on the canvas.' It distinguishes this tool from siblings by mentioning it as 'the classic finishing pass' and referencing a prerequisite step (pixel_resize_canvas) for edge cases.

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 states when to use the tool ('finishing pass') and gives a clear condition for when to first use pixel_resize_canvas (if the sprite touches the canvas edge). However, it does not explicitly exclude alternative tools or scenarios.

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