Add an ellipse/circle to the active document

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

With no annotations, the description carries the burden. It explains the coordinate system (points from top-left) and the active layer/document context, which is useful. However, it does not disclose whether the tool returns anything, how it affects selection or undo, or possible failure modes. It also leaves ambiguous whether fill/stroke are always applied, though the schema clarifies via 'Omit for no fill/stroke'.

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?

Two sentences with no wasted words. The primary action is front-loaded, followed by the coordinate clarification. 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?

For a drawing command with 6 parameters and no output schema, the description covers the essential behavior and coordinate system but omits details like explicit units for width/height, return value, and error conditions. It also does not mention how the shape is added (e.g., selection, stacking) or any side effects. Given the moderate complexity, it is adequate but not fully 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?

The description adds meaning to x and y by specifying the coordinate origin and units (points), which is critical and not in the schema. It implies width/height are in the same unit, and the reference to fill/stroke maps to the color parameters. Schema descriptions exist for fillColor and strokeColor but not for numeric params, so the description compensates for the 33% coverage gap.

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 the action ('Draws a filled/stroked ellipse') and the target ('active layer of the active document'), distinguishing it from sibling drawing tools like add_rectangle and add_text. The title reinforces the resource as an ellipse/circle.

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 use this tool versus alternatives, does not mention prerequisites (e.g., an open active document), and offers no exclusions or conditions. An agent must infer usage entirely from the purpose.

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