rhino_variable_blend_srf

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

With no annotations, the description carries the behavioral burden. It reveals a stateful precondition and states that the return is a dict with 'status' and 'command' keys, which suggests a command-wrapper behavior. However, it does not disclose side effects on the original surfaces, how variable radii are provided, or what happens if the selected edges are not naked.

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, front-loaded with the main action, and includes a necessary precondition. The Args/Returns boilerplate is slightly redundant given the schema, but it is minimal and does not waste significant 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?

Despite the output schema being present, key operational context is missing. The tool is called 'variable-radius' but has zero radius parameters and the description never explains how radii are specified. It also omits whether the original surfaces are altered or trimmed, and what the command flow is after pre-selection. An agent has enough to initiate the call but not enough to fully predict the outcome or troubleshoot.

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?

There are zero schema parameters and schema coverage is 100%, so the description does not need to explain parameters. It does mention a controller argument in the Args block, which is not in the schema; this adds slight ambiguity but does not hurt usability much.

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 'Create' and the resource 'variable-radius blend surface between two surface edges,' which is specific and distinguishes it from plain blend or fillet tools. However, it does not explicitly name a sibling alternative, so it stops short of a perfect score.

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 description gives a clear precondition: 'Pre-select the two naked edges before calling.' This tells the agent when and how to set up the operation. It does not mention when not to use the tool or name alternative tools, but the context is strong enough to score above average.

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