rhino_annotation_north_arrow

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

The annotations already indicate this is a write operation (readOnlyHint: false), and the description adds useful behavioral detail: the arrow is centered on location, and angle_deg rotates it clockwise from world +Y, which is non-obvious and important for site-north adjustments. There is no contradiction with the 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?

The description is two compact sentences. The main action is front-loaded, and the only extra detail—the rotation convention—is directly relevant to correct invocation. No wasted words.

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 simple annotation-creation tool with an output schema and default values in the input schema, the description covers the core action and the key non-obvious behavior. It does not enumerate optional fields, but those are documented in the schema, so nothing critical is missing for an agent to call 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?

Schema description coverage is reported as 0%, so the description must compensate. It does explain the two semantically rich parameters: location is the center point, and angle_deg rotates clockwise from world +Y. However, it leaves size, layer, style, name, and doc_id to the schema/defaults, so it only partially carries the parameter-documentation burden.

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 uses a specific verb and resource: 'Draw a north arrow centred on location.' This unambiguously identifies the tool's function and distinguishes it from sibling annotation tools like scale bars, callouts, and dimensions, which create different objects.

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 use case is implied: if an agent needs a north arrow annotation, this is the tool. However, the description does not explicitly state when to prefer this over other annotation tools, nor does it mention siblings such as rhino_annotation_scale_bar. There are no exclusions or alternative conditions provided.

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