rhino_add_directional_light

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

With no annotations, the description carries the full burden of behavioral disclosure, but it only restates the mutation ('Add a directional light to the scene'). It says nothing about coordinate system, default orientation, side effects, or whether existing lights are affected. No contradiction with annotations exists, but almost no behavioral context beyond the action is provided.

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 short, front-loaded, and contains no filler: a one-sentence purpose followed by a parameter line. It is easy to scan, though the parameter section is thinner than ideal.

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?

Although an output schema exists, this is a mutation tool with no annotations and no direction-convention guidance. It also lacks differentiation from the many other lighting-related sibling tools, so an agent lacks enough context to invoke it correctly in all situations.

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. The line 'direction_x, direction_y, direction_z: Light direction vector' is the only parameter documentation and at least groups the three values into a meaningful vector concept. However, it omits the coordinate system, normalization expectations, and how the default (0,0,-1) relates to scene orientation, so it only partially compensates for the missing schema descriptions.

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+resource ('Add a directional light to the scene'), clearly stating what the tool does. The noun 'directional light' inherently separates it from point and spot light siblings, though it never explicitly names an alternative, so it stops 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?

No guidance is provided on when to use this tool versus rhino_add_point_light, rhino_add_spotlight, or rhino_light_add. There are no exclusions, prerequisites, or context cues; an agent must infer the intended use from the name alone.

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