MCP: Bring Databricks provider to the state of the Rust Version (#3941)

## Summary

* Rewrite Databircks provider by directly porting
https://github.com/neondatabase/appdotbuild-agent/blob/main/edda/edda_integrations/src/databricks.rs
from the latest main branch
* Add pagination
* Add filtering
* Add table search
* Simplify the code

---------

Co-authored-by: Claude <[email protected]>

Author: fjakobs

experimental/apps-mcp/README.md

@@ -81,7 +81,7 @@ Understand your Databricks data before building:
 
 - **`databricks_list_catalogs`** - Discover available data catalogs
 - **`databricks_list_schemas`** - Browse schemas in a catalog
-- **`databricks_list_tables`** - Find tables in a schema
+- **`databricks_find_tables`** - Find tables in a schema
 - **`databricks_describe_table`** - Get table details, columns, and sample data
 - **`databricks_execute_query`** - Test queries and preview data
 

experimental/apps-mcp/cmd/apps_mcp.go

@@ -1,6 +1,9 @@
 package mcp
 
 import (
+	"errors"
+	"os"
+
 	"github.com/databricks/cli/cmd/root"
 	mcplib "github.com/databricks/cli/experimental/apps-mcp/lib"
 	"github.com/databricks/cli/experimental/apps-mcp/lib/server"
@@ -38,6 +41,13 @@ The server communicates via stdio using the Model Context Protocol.`,
 		RunE: func(cmd *cobra.Command, args []string) error {
 			ctx := cmd.Context()
 
+			if warehouseID == "" {
+				warehouseID = os.Getenv("DATABRICKS_WAREHOUSE_ID")
+				if warehouseID == "" {
+					return errors.New("DATABRICKS_WAREHOUSE_ID environment variable is required")
+				}
+			}
+
 			w := cmdctx.WorkspaceClient(ctx)
 
 			// Build MCP config from flags

experimental/apps-mcp/lib/mcp/server.go

@@ -43,6 +43,18 @@ func (s *Server) AddTool(tool *Tool, handler ToolHandler) {
 	}
 }
 
+// GetTools returns all registered tools.
+func (s *Server) GetTools() []*Tool {
+	s.toolsMu.RLock()
+	defer s.toolsMu.RUnlock()
+
+	tools := make([]*Tool, 0, len(s.tools))
+	for _, st := range s.tools {
+		tools = append(tools, st.tool)
+	}
+	return tools
+}
+
 // Run starts the MCP server with the given transport.
 func (s *Server) Run(ctx context.Context, transport *StdioTransport) error {
 	s.transport = transport

experimental/apps-mcp/lib/mcp/types.go

@@ -3,6 +3,7 @@ package mcp
 
 import (
 	"context"
+	"fmt"
 )
 
 // Implementation represents server or client implementation details.
@@ -41,3 +42,16 @@ type ToolHandler func(context.Context, *CallToolRequest) (*CallToolResult, error
 
 // ToolHandlerFor is a typed handler for tool calls with automatic marshaling.
 type ToolHandlerFor[In, Out any] func(context.Context, *CallToolRequest, In) (*CallToolResult, Out, error)
+
+func CreateNewTextContentResult(text string) *CallToolResult {
+	return &CallToolResult{
+		Content: []Content{&TextContent{Type: "text", Text: text}},
+	}
+}
+
+func CreateNewTextContentResultError(err error) *CallToolResult {
+	return &CallToolResult{
+		Content: []Content{&TextContent{Type: "text", Text: fmt.Sprintf("Error: %v", err)}},
+		IsError: true,
+	}
+}