rhino_cmd_area

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

With no annotations provided, the description carries the full behavioral burden. It does disclose that the tool reads the current selection and returns a Dict, but it omits critical operational details: result units, behavior when nothing is selected or the selection contains invalid geometry, and confirmation that this is a non-destructive read operation. The 'selected' input mechanism is also only implicit in the purpose clause, not stated as a prerequisite.

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 compact and front-loaded with the purpose statement in the first sentence. The Args and Returns sections are standard docstring format with no fluff. The Args line listing 'controller' is mildly redundant given the empty schema, but it does not materially waste space.

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 zero-parameter tool with an output schema present, the burden on the description is lighter. It is still missing actionable context: an agent is not told to ensure appropriate objects are selected before calling, what happens with an empty or invalid selection, or how this tool differs from the sibling rhino_area. The core purpose is covered, but these operational gaps keep it from being 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?

The input schema has zero properties, so the baseline of 4 applies. The description's Args section mentions a 'controller' parameter that does not appear in the schema, which is slightly anomalous, but since no arguments are required, the agent faces no parameter-construction burden. The description adds no param semantics, but none are needed here.

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 a specific verb and resource: 'Calculate the area of selected closed curves, hatches, or surfaces.' This clearly distinguishes it from length, volume, and distance siblings like rhino_curve_length, rhino_volume, and rhino_distance. However, it does not differentiate from the near-identically-named sibling rhino_area, which creates potential selection ambiguity.

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 'selected' qualifier implies the tool operates on the current Rhino document selection, and the geometry-type constraints are useful context. But there is no explicit when-to-use guidance, no mention of exclusions (e.g., open curves are not valid), and no reference to alternatives. Given the rhino_area sibling, the lack of explicit routing guidance is a real gap.

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