URDF

Use this skill for robot description outputs. URDF work is intentionally separate from ordinary CAD generation because the correctness questions are kinematic, XML, and mesh-reference oriented rather than primarily geometric.

Consumer-specific metadata is allowed when a downstream UI or simulator adapter expects it. Treat that metadata as generator-owned extension data rather than standard URDF.

Defer CAD handoff details to the CAD skill: read .agents/skills/cad/SKILL.md, then only load its references/rendering-and-explorer.md when a URDF needs a CAD Explorer link. If the local CAD skill is unavailable, use cad-skill as the fallback reference. Keep URDF-specific generation and explorer_metadata contracts in this skill.

Workflow

1. Treat the Python source that defines gen_urdf() as source of truth. Treat the configured .urdf file as generated.
2. For the gen_urdf() envelope contract, read references/generator-contract.md.
3. For robot description edits, read references/urdf-workflow.md.
4. Prioritize complete physical links: include inertial, visual, and collision for each link that represents physical robot geometry. Frame-only links may intentionally omit them.
5. Edit links, joints, limits, axes, origins, inertials, materials, visual/collision geometry, mesh filenames, and any consumer-specific sidecar metadata deliberately.
6. Regenerate only the explicit URDF target with scripts/gen_urdf/cli.py.
7. Use --summary for a compact robot/link/joint check after regeneration.
8. For validation expectations, read references/validation.md.
9. If URDF mesh references depend on changed CAD, mesh, or render outputs, regenerate only the affected explicit targets with the owning CAD or mesh workflow.
10. For CAD Explorer handoff of generated .urdf entries, use the CAD skill's Explorer handoff rules rather than duplicating link syntax here.

Commands

Run with the Python environment for the project or workspace. If the environment lacks the URDF validation runtime packages, install this skill's script dependencies from requirements.txt. Invoke the tool as a filesystem script, for example python <urdf-skill>/scripts/gen_urdf/cli.py .... Relative target paths are resolved from the current working directory; the tool does not prepend a project root.

• URDF sidecars: scripts/gen_urdf/cli.py

The command interface is target-explicit. Pass the Python generator that defines gen_urdf(); use --summary for a compact robot/link/joint check.

References

• URDF generation: references/gen-urdf.md
• Generator contract: references/generator-contract.md
• URDF edit workflow: references/urdf-workflow.md
• URDF validation: references/validation.md