feat: add ResourceLink type and parsing support

- Add ResourceLink type for tool result.
- Add NewResourceLink function to create ResourceLink instances.
- Add ResourceLink parsing support in ParseContent function.

Author: chenmingyong0423

mcp/types.go

@@ -865,6 +865,22 @@ type AudioContent struct {
 
 func (AudioContent) isContent() {}
 
+// ResourceLink represents a link to a resource that the client can access.
+type ResourceLink struct {
+	Annotated
+	Type string `json:"type"` // Must be "resource_link"
+	// The URI of the resource.
+	URI string `json:"uri"`
+	// The name of the resource.
+	Name string `json:"name"`
+	// The description of the resource.
+	Description string `json:"description"`
+	// The MIME type of the resource link.
+	MIMEType string `json:"mimeType"`
+}
+
+func (ResourceLink) isContent() {}
+
 // EmbeddedResource represents the contents of a resource, embedded into a prompt or tool call result.
 //
 // It is up to the client how best to render embedded resources for the

mcp/utils.go

@@ -222,6 +222,17 @@ func NewAudioContent(data, mimeType string) AudioContent {
 	}
 }
 
+// Helper function to create a new ResourceLink
+func NewResourceLink(uri, name, description, mimeType string) ResourceLink {
+	return ResourceLink{
+		Type:        "resource_link",
+		URI:         uri,
+		Name:        name,
+		MIMEType:    mimeType,
+		Description: description,
+	}
+}
+
 // Helper function to create a new EmbeddedResource
 func NewEmbeddedResource(resource ResourceContents) EmbeddedResource {
 	return EmbeddedResource{
@@ -476,6 +487,16 @@ func ParseContent(contentMap map[string]any) (Content, error) {
 		}
 		return NewAudioContent(data, mimeType), nil
 
+	case "resource_link":
+		uri := ExtractString(contentMap, "uri")
+		name := ExtractString(contentMap, "name")
+		description := ExtractString(contentMap, "description")
+		mimeType := ExtractString(contentMap, "mimeType")
+		if uri == "" || name == "" || description == "" || mimeType == "" {
+			return nil, fmt.Errorf("resource_link uri, name, description or mimeType is missing")
+		}
+		return NewResourceLink(uri, name, description, mimeType), nil
+
 	case "resource":
 		resourceMap := ExtractMap(contentMap, "resource")
 		if resourceMap == nil {