pixel_draw_pixels

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

The description adds substantial behavioral details beyond annotations: out-of-bounds handling, transparent color erasing, batch default color, return JSON structure, and preview behavior. It aligns with annotations (destructive, idempotent) and adds context.

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 efficient: first sentence states purpose, then details. It uses bullet points for return format and examples, no redundant fluff. Every sentence adds value.

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 (4 parameters, batch behavior, preview, error handling), the description covers key behaviors. It lacks explicit mention of output schema (but none exists) and path format, but schema compensates. Sufficient for an AI agent.

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?

While the schema provides descriptions for each parameter, the tool description adds context: default color behavior, transparent as eraser, out-of-bounds skipped, and preview returns image. It doesn't cover every parameter (e.g., path format) but adds meaningful explanations.

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 'Set individual pixels on a canvas in one batch' with a specific verb ('Set') and resource ('pixels on a canvas'). It distinguishes this tool from siblings like pixel_draw_line and pixel_draw_rect by focusing on individual pixel manipulation in batch operations.

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 advises batching multiple points per call ('one call per sprite region, not one call per pixel'), providing clear usage guidance. It also mentions that out-of-bounds points are skipped, but does not explicitly state when to use alternatives or when not to use this tool.

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