plasticity_measure_planar_faces

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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=false, so the safety profile is covered. The description adds real value beyond that: it defines the computed quantities, their units (mm), and the supporting-plane interpretation, plus explicit scope exclusions. It does not describe result shape or how the angular tolerance affects the parallel/angle decision.

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?

Two tightly written sentences, with the primary computation front-loaded before the caveat. Minor deduction because the trailing parenthetical '(separationKind='supporting-planes')' references a field absent from the schema and adds ambiguity rather than clarity.

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?

With no output schema and no parameter documentation, the description carries the conceptual burden and does it well, but leaves an agent unable to determine what 'revision' must be or how 'angularToleranceDeg' behaves. Adequate for understanding the measurement's meaning, incomplete for calling it 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 0% and all 4 parameters are undocumented anywhere. The description never explains 'first'/'second' nesting, 'revision', or 'angularToleranceDeg' (which is presumably the parallelism threshold but is unstated). The only quasi-parameter mention, separationKind='supporting-planes', does not even appear in the schema, so it does not compensate.

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?

States a specific verb and resource ('measure the angle between two current planar B-Rep faces') and specifies the exact quantity returned when parallel (signed/absolute separation of infinite supporting planes, in mm). This is enough to distinguish it from siblings like plasticity_measure_parallel_planar_face_clearance or plasticity_measure_point_to_planar_face without opening any schema.

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?

Explicitly gives both a when-to-use condition ('use only when supporting-plane spacing is the intended quantity') and when-not ('does not test overlap of the trimmed faces or measure their actual gap/clearance'). It stops short of naming the alternative tool to reach for in the excluded cases, which keeps it from a 5.

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