Allow structured outputs via function calling (#828)

chat.go

@@ -264,6 +264,7 @@ type ToolFunction struct {
 type FunctionDefinition struct {
 	Name        string `json:"name"`
 	Description string `json:"description,omitempty"`
+	Strict      bool   `json:"strict,omitempty"`
 	// Parameters is an object describing the function.
 	// You can pass json.RawMessage to describe the schema,
 	// or you can pass in a struct which serializes to the proper JSON schema.