create_rectangle

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

With no annotations, the description carries the behavioral burden and does add non-obvious context: the default unit (mm), the Y-up coordinate convention, that (x,y) is the lower-left corner, and how the shape is stored ([x,y,width,height] in mm, cornerRadius in properties). It says nothing about return values, permissions, or side effects on layers, so it is helpful but incomplete.

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 dense sentences with the shape definition front-loaded and zero filler. It is efficient, though the storage-format clause is somewhat cryptic without further explanation of the property key.

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 7-parameter creation tool with no annotations and no output schema, the description covers the geometry semantics well but omits the `layer` parameter and any statement about what the tool returns or where the entity is placed. Adequate but with visible gaps.

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 must compensate, and it does for six of seven parameters: x, y, width, height, cornerRadius, and the unit enum (described only as 'default mm'). The `layer` parameter is left completely undocumented, which is the one clear 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 states precisely what is created (an axis-aligned rectangle) and defines its geometry via corner, width, height and optional cornerRadius, which clearly separates it from the curved/3D siblings like create_circle or create_box. It does not explicitly name a sibling alternative, so it falls short of a 5.

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?

There is no indication of when to choose this over create_polygon, create_box, or other primitives, nor any prerequisites or exclusions. An agent must infer usage entirely from the name and the shape definition.

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