rhino_fillet_curves

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

Annotations indicate this is a mutation (readOnlyHint false) and not destructive (destructiveHint false). The description only says 'create', which aligns with the annotations. However, it does not disclose what happens to the original curves (e.g., whether they are trimmed), the role of the 'join' parameter, or that the operation may fail if curves do not intersect. With no annotation coverage for these nuances, the description carries the burden and fails to provide them.

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 a single sentence with no unnecessary words. It is front-loaded with the core action ('Create a fillet arc') and gives just enough detail about location. However, it is so brief that it forgoes essential operational context, though from a pure conciseness standpoint it is efficient. A 4 is appropriate for being crisp, but it pays for brevity in other dimensions.

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?

This is a creation operation with moderate complexity (requires two curve GUIDs and a radius). The description omits prerequisites (intersection), the effect on original geometry (trimming/joining), and potential error conditions (invalid radius, non-intersecting curves). While an output schema exists, it does not cover these execution conditions. The description is too thin for an agent to predict side effects or avoid failures.

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 schema itself provides descriptions for each parameter (e.g., 'GUID of the first curve', 'Fillet radius'), but the description adds no extra meaning. The context signal shows schema description coverage of 0%, indicating the tool description does not compensate for parameter understanding. Since there are several parameters (curve1_guid, curve2_guid, radius, join) and the description doesn't clarify their interplay (e.g., that join trims and joins results), the parameter semantics are insufficient.

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 ('create') and resource ('fillet arc') and provides location context ('between two curves at their intersection'). This clearly differentiates it from sister tools like rhino_fillet_edge, which works on surfaces. However, it does not explicitly mention that it operates on curves in a way that could conflict with rhino_create_arc, though the context makes that clear.

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 given about when to use this tool versus alternatives. It does not mention prerequisites (curves must intersect), nor does it suggest specific conditions for using rhino_fillet_edge or other curve tools. The description is purely declarative with no 'when-to-use' or 'when-not-to-use' information.

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