Type Alias: SurfaceMode

SurfaceMode = "auto" | "system-prompt" | "tool-only" | "both"

Defined in: src/lib/injection-engine/factories/defineSkill.ts:58

Where the Skill's body lands when activated.

• 'system-prompt' — body appended to the system slot on the iteration after activation. Best on Claude ≥ 3.5 (training-time adherence to system-prompt instructions is strong).
• 'tool-only' — body delivered ONLY via the read_skill tool's result. Recency-first by protocol; doesn't rely on the model's training to honor system-prompt anchoring. Default for every non-Claude provider.
• 'both' — body lands in both the system slot AND the tool result. Belt-and-suspenders for high-stakes Skills on long-context runs.
• 'auto' — the library picks per provider via resolveSurfaceMode. 'both' on Claude ≥ 3.5; 'tool-only' everywhere else.

v2.5 runtime dispatch (Block C): modes now route differently:

• 'system-prompt' → body in system slot, tool result is confirmation
• 'tool-only' → body SUPPRESSED from system slot, tool result IS the body
• 'both' → body in system slot AND in tool result
• 'auto' → keeps v2.4 behavior (body in system slot, tool result is confirmation) The Block A4 cascade resolves 'auto' against provider/model context at a future runtime layer (Claude ≥ 3.5 → 'both'; else 'tool-only').