pixel_create_canvas

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

The description discloses key behaviors: true-size canvas, automatic parent directory creation, refusal to replace without overwrite=true, and return format (JSON plus optional preview image). Annotations are sparse, so the description adds valuable transparency beyond them.

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 concise with no redundant sentences. It is well-structured: purpose, size advice, behavioral notes, and return info, all front-loaded for quick comprehension.

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 has 6 parameters and no output schema, the description covers essential aspects: purpose, size recommendations, automatic directory creation, overwrite behavior, preview option, and return format. It lacks details on error types and background initialization, but overall is fairly complete.

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?

Despite 0% schema description coverage, the description mentions overwrite and preview parameters explicitly. However, it does not explain path, width, height, or background parameters, relying on the schema's own descriptions. This partial coverage limits the added value.

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 'Create a new pixel art canvas saved as a PNG file,' which is a specific verb+resource pair. It distinguishes itself from siblings like pixel_draw_pixels and pixel_export_png by focusing on canvas creation.

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 provides guidance on canvas size ('keep sprites small') and suggests using pixel_export_png for upscaling later. It also clarifies that overwriting requires overwrite=true, giving clear context for when to use this tool over alternatives.

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