figma_create_ellipse

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

Annotations already indicate non-readonly, non-destructive, non-idempotent behavior. The description adds that ellipses can include arcs and recommends DS color variables, providing some additional context beyond annotations.

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?

Three concise sentences with no waste. The first sentence states purpose, the second adds a key feature, the third gives a usage hint. Front-loaded and efficient.

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 complex tool with 15 parameters and a nested object, the description covers core purpose and two key features. It could mention positioning defaults or that parentNodeId is optional, but with high schema coverage, it remains adequate.

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?

Input schema has 100% description coverage, so baseline is 3. The description adds value by highlighting arcData parameter and recommending DS color variables over hex, which guides the agent on preferred usage.

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 'Create an ellipse in Figma' with a specific verb and resource. It also mentions arc support for donut segments, which distinguishes it from sibling tools like figma_create_rectangle or figma_create_text.

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 implies usage for creating ellipses but does not explicitly state when to use this tool versus alternatives. It provides a guideline to use DS color variables, but no when-to-use or when-not-to-use guidance.

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