create_ellipse

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

Annotations already indicate non-read-only and non-destructive behavior, so the description adds a return shape ({ ok, nodeId, name, type }) and default parent context. It does not disclose side effects on existing nodes, coordinate system details, or error behavior, but this is acceptable given annotation coverage and the simple creation task.

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, front-loaded with the core action, and every clause earns its place—covers default behavior, the circle condition, and a pointer to a related tool. No redundancy or filler.

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?

Without an output schema, the description provides the return shape, which is valuable. It covers the main functionality (create, optional attributes, parent default) and directs to set_arc for further shaping. It omits potential edge cases like invalid parentId or coordinate system units, but for a creation tool with a well-described schema, this is adequate and near 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?

Schema covers 100% of parameters with descriptions, so baseline is 3. The description adds meaningful nuance: 'circle when width equals height' clarifies the relationship between width and height, and 'default: current page' reinforces the parentId default (already in schema but helpful to highlight). No parameter semantics are contradicted.

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 verb and resource: 'Create an ellipse', with a helpful clarification that equal width/height produces a circle. It distinguishes from sibling tools like create_rectangle and create_text by focusing on ellipse-specific behavior, including optional attributes and default parent.

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?

Provides clear context: the tool creates an ellipse with optional sizing/naming/positioning under a parent (default current page). It explicitly routes to set_arc for transforming into pie/arc/ring, giving an alternative for subsequent needs. It does not explicitly contrast with create_rectangle, but the resource type is unambiguous.

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