Tool Builder Layout
The tool builder uses a 3-column layout:| Column | Purpose |
|---|---|
| Left | SQL editor (Monaco) for writing the query |
| Center | Parameter designer for defining inputs |
| Right | Preview panel with execution results and code output |
Writing SQL Queries
Use:param_name to define query parameters:
Parameter Designer
Each detected parameter can be configured:| Field | Description |
|---|---|
| Name | Auto-detected from :name in SQL |
| Type | string, integer, number, or boolean |
| Required | Whether the client must provide this parameter |
| Default | Default value if not supplied |
| Enum Values | Restrict input to allowed values (comma-separated) |
| Description | Human-readable description shown to MCP clients |
SQL Preview
The right column includes a Preview tab for test-executing your query:- Fill in test values for each parameter
- Click Run Preview
- Results display in a table format
Preview queries execute in read-only mode with an automatic
LIMIT applied.Tool Metadata
| Field | Description |
|---|---|
| Name | Tool identifier (used by MCP clients to call the tool) |
| Description | What the tool does (shown to LLMs for tool selection) |
| Tags | Categorical labels for organization |
| Cache TTL | How long results are cached (in seconds, 0 = no cache) |
Annotations
Annotations provide safety hints to MCP clients:| Annotation | Description |
|---|---|
read_only | Tool only reads data |
destructive | Tool may delete or alter data |
open_world | Tool interacts with external systems |
idempotent | Repeated calls produce the same result |
Code Preview
The Code tab shows the generated Python code that will run inside the deployed FastMCP server. This is read-only and updates automatically.Connection Binding
Each tool must be bound to a database connection. Select the connection from the dropdown at the top of the tool builder.Duplicating Tools
Open a tool and click Duplicate to create a copy with the name<original>_copy.
Keyboard Shortcuts
| Shortcut | Action |
|---|---|
Ctrl+S | Save the current tool |
Ctrl+Enter | Run preview execution |
See Also
Connections
Create and manage the database connections that tools query against
Resources
Expose data as readable MCP resources with URI templates
Prompts
Design reusable prompt templates for LLM interactions
Flow Editor
Manage tools visually on the drag-and-drop canvas
Deployment
Deploy your tools as a running MCP server
REST API
Tool CRUD endpoints in the REST API