Indicates whether this modality is allowed/supported.
Maximum count of items per message for this modality. Null means no limit.
Maximum dimension (width/height for images). Only applicable for image modality. Null means no limit.
Maximum size in bytes for this modality. Null means no limit.
The source of the limits ('Agent', 'Model', 'System', or 'Default')
Supported formats as a comma-delimited string (e.g., "image/png, image/jpeg"). Null means all formats.
Represents the effective limits for a specific modality (e.g., Image, Audio). These limits are resolved using the precedence chain: Agent → Model → System → Defaults.