urdflisted

# URDF Provenance: maintained in [earthtojake/text-to-cad](https://github.com/earthtojake/text-to-cad). Use the installed local skill files as the runtime source of truth; the repository link is only for provenance and release review. Use this skill for URDF robot-description outputs. Treat URDF work as constrained kinematic modeling, not just XML writing. The main correctness risks are frame placement, joint-axis semantics, unit consistency, mesh scale, inertial data, and generated-artifact drift. ## Core Rules 1. Treat the Python source that defines `gen_urdf()` as the source of truth. Treat configured `.urdf` files as generated artifacts. 2. Generate only explicit URDF targets. Do not regenerate unrelated CAD, mesh, render, SRDF, SDF, or simulator artifacts from this skill. 3. The `scripts/urdf` generator validates generated URDFs by default. Do not use or document a separate `validate` command. 4. Before writing or changing URDF XML, establish the robot's frame, joint, geometry, unit, and assumption ledger. See `references/design-ledger.md`. 5. Use URDF frame semantics exactly. Joint origins, link frames, joint axes, and visual/collision/inertial origins use different reference frames. See `references/frame-semantics.md`. 6. Do not infer spatial transforms, mesh units, handedness, axes, or joint signs from vague prose. Use CAD transforms, dimensioned drawings, measured values, existing source data, or explicit documented assumptions. 7. Prefer simple, auditable genera