draw_pixels_at

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

With no annotations, the description carries the full behavioral burden. It discloses one side effect (creating the cel when requested), but does not state whether existing pixels are overwritten, how coordinates are interpreted, or what happens when create_if_missing is false. For a mutating draw tool this is a significant gap.

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?

One compact sentence that front-loads the verb and target resource. No wasted words, and the optional cel-creation behavior is placed at the end.

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 5-parameter mutation tool with no annotations and no output schema, this is too thin: no coordinate system, no overwrite semantics, no error/return behavior, and no hint of what the function produces. The available context comes almost entirely from the schema and sibling names.

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 needed to explain all five parameters. It only gestures at layer_name/frame_index with 'named layer and animation frame' and at create_if_missing with 'when requested'; filename and the required x/y/color structure of pixels are left to inference.

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?

States a specific action and resource: drawing explicit pixel data onto a named layer and animation frame, with a cel-creation side effect. This is clear enough to distinguish from shape-drawing tools, though it never explicitly contrasts with the similar draw_pixels sibling.

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?

No guidance on when to choose this tool over alternatives such as draw_pixels or the other _at drawing variants. 'Explicit pixels' hints at pixel-level editing, but the description does not state use cases, exclusions, or prerequisites.

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