draw_ellipse

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

No annotations are provided, so the description bears the full responsibility for disclosing side effects. It only explains the mathematical parameterization (center, major-axis endpoint, ratio) but omits what the tool does (creates an ellipse entity), how it interacts with the current drawing state (e.g., layer, color), or whether any data is returned. The description gives no indication of the tool's behavior as a drawing operation.

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 sentence, every word is informative. It front-loads the core geometry and includes no filler or repetition. Structure is ideal for a parameter-heavy primitive.

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?

The description defines geometry but fails to state that this tool draws an ellipse entity. Given the tool name and sibling list, an agent might infer this, but for a drawing tool with an output schema, it would benefit from a short action statement. The parameter semantics are complete, but the lack of behavioral context makes it only minimally viable for an agent to choose this correctly.

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?

With 0% schema description coverage, the description compensates well by explicitly defining cx, cy, major_dx, major_dy, and ratio. It clarifies that major_dx/dy are relative to the center and that ratio is minor/major, which are non-obvious and critical for correct invocation. Only the layer parameter is not mentioned, but its purpose is self-evident.

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 identifies the tool as 'Ellipse' and specifies its geometric parameters (center, major-axis endpoint, ratio), which distinguishes it from circle/arc siblings. However, it lacks an explicit action verb like 'draws' or 'creates,' relying on the tool name to convey the operation. This is clear but not fully explicit.

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 draw_circle, draw_arc, or other drawing tools. It doesn't mention any prerequisites (e.g., current layer) or alternatives. There is no usage context beyond parameter definitions.

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