draw_circle_at

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

There are no annotations, so the description carries the full burden of behavioral disclosure, but it only says a circle is drawn. It does not mention whether existing pixels are overwritten, what happens if the layer or frame is missing despite create_if_missing, what coordinate system is used, or whether filling and color are part of the default behavior. The description is not contradictory, but it leaves major behavioral expectations unstated.

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 a single short sentence with no filler, and the main action is front-loaded. It earns its place but is not perfectly efficient because 'ellipse-bounded' is unusual jargon that is never explained. Still, this is a concise and well-structured statement.

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 nine parameters, no annotations, zero schema description coverage, and no output schema, a one-sentence description is far from complete. The agent cannot tell what the function returns, whether it mutates existing pixels, how coordinate bounds are handled, or what the defaults of fill/color/create_if_missing mean behaviorally. This is substantially inadequate for reliable tool selection and invocation.

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 should compensate, but it explains almost none of the nine parameters. 'Center_x,' 'center_y,' and 'radius' are loosely implied by drawing a circle, and 'named layer' maps to layer_name, but fill, color, create_if_missing, frame_index, and filename are given no added meaning beyond their names. The description adds minimal value over the raw schema.

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 states a specific action ('Draw'), an object ('an ellipse-bounded circle'), and a target ('a named layer and animation frame'), which makes the core operation clear. It does not explicitly distinguish itself from sibling tools like draw_circle or draw_ellipse_at, though the phrase 'named layer and animation frame' hints at the difference. Overall, the purpose is clear but sibling differentiation is left implicit.

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 no guidance on when to choose draw_circle_at versus draw_circle, draw_ellipse_at, draw_rectangle_at, or the many other drawing tools. It does not state prerequisites, such as whether the layer or frame must already exist, nor does it mention any conditions that would make this tool preferable. The agent is left to infer usage context from the tool name and sibling list.

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