draw_pixels

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

With no annotations provided, the description carries the full disclosure burden. It only states that pixels are drawn, without mentioning whether this overwrites existing pixels, how out-of-bounds coordinates are handled, whether blending applies, or what happens if no active cel exists. This leaves important behavioral traits undocumented.

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 and front-loaded, with no fluff. However, the brevity comes at the cost of omitting needed parameter and usage context, so it is minimally adequate rather than well-rounded.

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 two-required-parameter tool with no annotations and no output schema, this description is incomplete. An agent still cannot confidently determine how filename selects the target, what coordinate system pixels use, or how 'active cel' is resolved.

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 explaining the parameters, but it does not. It never explains filename, the coordinate space for x/y, or the accepted color format beyond what the schema's type and pattern already state.

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 uses a specific verb and resource: 'Draw explicit pixels on the active cel.' It clearly identifies the operation and the target. However, it does not explicitly differentiate from similar sibling tools like draw_pixels_at or draw_line, relying on the phrase 'active cel' to distinguish the scope.

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 gives no guidance on when to use this tool versus alternatives such as draw_pixels_at, draw_rectangle, or fill_area. It also does not state any preconditions, such as needing an active cel or how filename relates to choosing the target sprite.

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