#[derive(Debug, thiserror::Error)]
pub enum MetadataError {
#[error("McpToolResultMetadata: mcp_execution_id cannot be empty")]
MissingExecutionId,
#[error("CallToolResult._meta is missing (required for MCP execution tracking)")]
MetaMissing,
#[error("Failed to serialize McpToolResultMetadata as JSON object")]
NotJsonObject,
#[error(transparent)]
Serde(#[from] serde_json::Error),
}