Add Gear

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

Beyond the annotations (readOnlyHint=false, destructiveHint=false), the description discloses that the result is extruded to a solid, lists the exact return fields, and explains meshing behavior for external gears (spacing equal to pitch_radius_a + pitch_radius_b plus half-tooth phasing). This adds meaningful behavioral context beyond what annotations convey.

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 efficiently structured: it opens with the core purpose, then systematically lists each parameter, followed by the return fields and a practical meshing note. Every sentence provides essential information without redundancy or filler.

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?

Given 7 parameters, no output schema, and minimal annotations, this description gives the agent everything needed to call the tool correctly: parameter meanings, formulas, defaults, return values, and even inter-gear spacing guidance. Nothing critical is missing for successful invocation.

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?

With 0% schema description coverage, the description fully compensates by explaining teeth (minimum 3), module with the pitch diameter formula, height as extrusion thickness, pressure_angle with default, external as an internal/ring toggle, and placement as an optional translation. It omits only the trivial 'name' parameter which has a default.

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 tool's function: 'Add an involute spur gear (FreeCAD's core involute generator), extruded to a solid.' It uses a specific verb and resource, and mentions the FreeCAD generator, which differentiates it from sibling tools like add_rack, add_sprocket, and add_pulley.

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 provides comprehensive parameter semantics and a pitch diameter formula, making the usage context clear. However, it does not explicitly mention alternatives or when not to use this tool, leaving the agent to infer from sibling names. This is a clear context without exclusions, but not fully explicit about alternative selection.

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