sdflisted

# SDF 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 when the deliverable is an SDFormat document or a Python `gen_sdf()` source. SDFormat describes simulator and world behavior: models, worlds, frames, poses, links, joints, inertials, visuals, collisions, sensors, lights, physics, plugins, includes, and simulator metadata. This skill is for **SDFormat**, not signed-distance-field geometry. ## Core rules 1. Treat the Python file defining `gen_sdf()` as source of truth. Treat configured `.sdf` files as generated artifacts unless the user explicitly asks for direct XML editing. 2. Identify the target consumer before editing: Gazebo/libsdformat version, another simulator, visualization-only tooling, model package, or world handoff. 3. Decide document kind: model-level SDF, world-level SDF, or model-in-world. Prefer model-level SDF for reusable robot/object exports. 4. Use SI units unless the target explicitly requires otherwise: meters, kilograms, seconds, radians. 5. Prefer `version="1.12"` for new outputs unless the target consumer constrains the version. 6. Establish the design ledger before writing poses, frames, joint axes, mesh scales, inertials, sensors, or plugins. Use `references/design-ledger.md` and `references/llm-guardrails.md`. 7. Do not infer spatial transforms from