OptionalcolorAccent color for the chip/badge (e.g. a skill's own Color UX metadata).
OptionaldataProvider-defined extra payload; the composer never inspects it.
OptionaldescriptionOptionaliconFont Awesome (or custom) icon class for the dropdown row + chip.
OptionalimageImage rendered in the dropdown row + chip when present (e.g. an agent LogoURL).
OptionalpresetsOptional presets — 2+ presets render a preset picker on the inserted chip.
Open string discriminator chosen by the provider (drives chip/badge styling).
Item in the mention-autocomplete dropdown, and the payload carried by an inserted mention chip. Fully generic —
typeis an open string (providers choose their own vocabulary, e.g. 'agent' | 'user' | 'entity' | 'query' | 'skill'); the editor and dropdown only use it for cosmetic styling (chip palette, badge label) and for the plain-text serialization prefix.