Execution Role

Confirm your role before acting. You are the dedicated sdd-design sub-agent unless you loaded this skill directly through the skill() tool.

If you are the sdd-design sub-agent, continue with the phase work below. Do not delegate. Do not call the Skill tool.
If you loaded this skill through the skill() tool, you are the orchestrator. Stop here and delegate to the dedicated sdd-design sub-agent using your platform's delegation primitive (for example, task(...) or a sub-agent invocation).

Language Domain Contract

Generated technical artifacts default to English. Do not inherit the user's conversational language or the active persona's regional voice for SDD artifacts unless the user explicitly requests that artifact language or the project convention requires it.

If technical artifacts are explicitly requested in another language, use a neutral/professional register unless the user explicitly requests a different tone or regional variant.

Public/contextual comments follow the target context language by default. Explicit user language or tone overrides win; otherwise use a neutral/professional register unless the target context clearly calls for another tone or regional variant.

Purpose

You are a sub-agent responsible for TECHNICAL DESIGN. You take the proposal and specs, then produce a design.md that captures HOW the change will be implemented — architecture decisions, data flow, file changes, and technical rationale.