---
title: "Building SQL Tools"
description: "Step-by-step guide to creating custom YAML SQL tools for IBM i database operations with examples and best practices."
---
This guide walks you through creating custom YAML SQL tools from basic queries to advanced enterprise operations. You'll learn to build tools that integrate seamlessly with AI agents while maintaining IBM i security and performance standards.
<Note>
**Prerequisites**: Basic SQL knowledge and familiarity with IBM i system services (QSYS2 schema). For YAML syntax, any text editor will work, but one with YAML syntax highlighting is recommended.
</Note>
## Your First SQL Tool
Let's start with a simple tool that lists active jobs. This example introduces the core concepts you'll use in all YAML SQL tools.
### Step 1: Create the Configuration File
Create a new file called `my-first-tools.yaml`:
```yaml
# Database connection configuration
sources:
ibmi-system:
host: ${DB2i_HOST}
user: ${DB2i_USER}
password: ${DB2i_PASS}
port: 8076
ignore-unauthorized: true # Development only
# Define your SQL tools
tools:
list_active_jobs:
source: ibmi-system
description: "List currently active jobs on the IBM i system"
statement: |
SELECT job_name, user_name, job_status, cpu_used, elapsed_time
FROM qsys2.active_job_info
WHERE job_status = 'ACTIVE'
ORDER BY cpu_used DESC
FETCH FIRST 20 ROWS ONLY
parameters: []
# Organize tools into logical groups
toolsets:
basic_monitoring:
title: "Basic System Monitoring"
description: "Simple tools for monitoring system activity"
tools:
- list_active_jobs
```
### Step 2: Test Your Tool
Start the MCP server with your new configuration:
```bash
TOOLS_YAML_PATH=my-first-tools.yaml npm run start:http
```
Use the MCP Inspector to test your tool:
```bash
npm run mcp-inspector
```
<Note>
**Development Tip**: Always start with simple, parameter-free tools to verify your connection and SQL syntax. You can add complexity incrementally as you gain confidence with the YAML structure.
</Note>
## Adding Parameters
Parameters make tools dynamic and reusable. Let's enhance our job listing tool with filtering capabilities:
<Card title="Parameter Examples Guide" icon="book-open" href="/sql-tools/parameter-guide">
**Need comprehensive examples?** See the Parameter Guide for detailed examples of all parameter types (string, integer, float, boolean, array) with validation patterns and best practices.
</Card>
<Tabs>
<Tab title="Basic Parameters">
```yaml
tools:
list_jobs_by_user:
source: ibmi-system
description: "List active jobs for a specific user"
parameters:
- name: user_name
type: string
required: true
description: "IBM i user profile name (uppercase)"
pattern: "^[A-Z][A-Z0-9_]*$"
maxLength: 10
statement: |
SELECT job_name, job_status, cpu_used, elapsed_time
FROM qsys2.active_job_info
WHERE user_name = :user_name
AND job_status = 'ACTIVE'
ORDER BY cpu_used DESC
FETCH FIRST 50 ROWS ONLY
```
</Tab>
<Tab title="Optional Parameters">
```yaml
tools:
flexible_job_search:
source: ibmi-system
description: "Search jobs with optional filtering"
parameters:
- name: user_filter
type: string
required: false
description: "Optional user name filter"
- name: max_rows
type: integer
default: 25
minimum: 1
maximum: 100
description: "Maximum number of jobs to return"
statement: |
SELECT job_name, user_name, job_status, cpu_used
FROM qsys2.active_job_info
WHERE (:user_filter IS NULL OR user_name = :user_filter)
AND job_status = 'ACTIVE'
ORDER BY cpu_used DESC
FETCH FIRST :max_rows ROWS ONLY
```
</Tab>
<Tab title="Enum Parameters">
```yaml
tools:
jobs_by_status:
source: ibmi-system
description: "List jobs filtered by job status"
parameters:
- name: status
type: string
enum: ["ACTIVE", "ENDED", "OUTQ", "MSGW"]
default: "ACTIVE"
description: "Job status to filter by"
statement: |
SELECT job_name, user_name, job_status,
job_type, subsystem, elapsed_time
FROM qsys2.active_job_info
WHERE job_status = :status
ORDER BY elapsed_time DESC
FETCH FIRST 30 ROWS ONLY
```
</Tab>
</Tabs>
### Parameter Validation
The MCP server automatically validates parameters before executing SQL:
```yaml
parameters:
- name: library_name
type: string
required: true
pattern: "^[A-Z][A-Z0-9_]*$" # IBM i naming rules
maxLength: 10
description: "IBM i library name (must be uppercase alphanumeric)"
- name: row_limit
type: integer
minimum: 1
maximum: 1000
default: 50
description: "Number of rows to return (1-1000)"
```
<Warning>
**Security Note**: Parameter validation is your first line of defense against invalid input. Always include appropriate constraints, especially for string parameters that could be used in injection attacks.
</Warning>
## Complete Example: Employee Information Tools
The `tools/sample/employee-info.yaml` file demonstrates a comprehensive set of tools using the IBM i SAMPLE schema. This example showcases **all five parameter types**, validation patterns, and SQL techniques in a single, production-ready configuration.
<Info>
**Why This Example Matters**: Rather than showing isolated snippets, this complete file demonstrates how real-world tools are structured, how parameters work together, and how SQL patterns combine to create powerful data operations.
</Info>
### Overview
**File Location:** `tools/sample/employee-info.yaml`
**Purpose:** Provide HR and project management capabilities using IBM i's SAMPLE database (EMPLOYEE, DEPARTMENT, PROJECT tables)
**What You'll Learn:**
- All 5 parameter types (string, integer, float, boolean, array) in production context
- Real-world SQL patterns: joins, self-joins, aggregations, pagination
- Parameter validation strategies
- Toolset organization for discoverability
---
### Source Configuration
Every YAML file starts with a source definition:
```yaml
sources:
ibmi-sample:
host: ${DB2i_HOST}
user: ${DB2i_USER}
password: ${DB2i_PASS}
port: 8076
ignore-unauthorized: true
```
<Note>
**Source Reuse**: This source is reused by all 8 tools in the file. Define sources once at the top, reference them in each tool using the `source` field. This ensures consistent connection settings and simplifies credential management.
</Note>
---
### Tool 1: String Parameters with Pattern Validation
**Tool:** `get_employee_details`
**Demonstrates:** String pattern validation, table joins, self-joins for hierarchical data
```yaml
get_employee_details:
source: ibmi-sample
description: Retrieve detailed information about an employee including department and manager
statement: |
SELECT
E.EMPNO,
E.FIRSTNME,
E.MIDINIT,
E.LASTNAME,
E.JOB,
E.HIREDATE,
E.SALARY,
E.BONUS,
E.WORKDEPT,
D.DEPTNAME,
D.LOCATION,
M.FIRSTNME AS MGR_FIRSTNME,
M.LASTNAME AS MGR_LASTNAME
FROM SAMPLE.EMPLOYEE E
LEFT JOIN SAMPLE.DEPARTMENT D ON E.WORKDEPT = D.DEPTNO
LEFT JOIN SAMPLE.EMPLOYEE M ON D.MGRNO = M.EMPNO
WHERE E.EMPNO = :employee_id
parameters:
- name: employee_id
type: string
description: "Employee ID (e.g., '000010') - Must be 6 digits"
required: true
pattern: "^[0-9]{6}$"
```
**Key Techniques:**
- **Pattern validation:** `^[0-9]{6}$` enforces exactly 6 digits
- **LEFT JOIN:** Handles missing departments or managers gracefully
- **Self-join:** `EMPLOYEE M` retrieves manager information by joining EMPLOYEE to itself
- **Descriptive aliases:** `MGR_FIRSTNME`, `MGR_LASTNAME` clarify the data source
**MCP Tool Call:**
```json
{
"name": "get_employee_details",
"arguments": {
"employee_id": "000010"
}
}
```
---
### Tool 2 & 3: String Enum Parameters
**Tools:** `find_employees_by_department`, `find_employees_by_job`
**Demonstrates:** Enum constraints for controlled value selection
<Tabs>
<Tab title="Department Filter">
```yaml
find_employees_by_department:
source: ibmi-sample
description: List employees in a specific department
statement: |
SELECT
E.EMPNO,
E.FIRSTNME,
E.MIDINIT,
E.LASTNAME,
E.JOB,
E.HIREDATE,
E.SALARY
FROM SAMPLE.EMPLOYEE E
WHERE E.WORKDEPT = :department_id
ORDER BY E.LASTNAME, E.FIRSTNME
parameters:
- name: department_id
type: string
description: "Department ID - Select from predefined departments"
required: true
enum: ["A00", "B01", "C01", "D01", "E01"]
```
</Tab>
<Tab title="Job Title Filter">
```yaml
find_employees_by_job:
source: ibmi-sample
description: Find employees with a specific job title
statement: |
SELECT
E.EMPNO,
E.FIRSTNME,
E.MIDINIT,
E.LASTNAME,
E.WORKDEPT,
D.DEPTNAME,
E.HIREDATE,
E.SALARY
FROM SAMPLE.EMPLOYEE E
LEFT JOIN SAMPLE.DEPARTMENT D ON E.WORKDEPT = D.DEPTNO
WHERE E.JOB = :job_title
ORDER BY E.LASTNAME, E.FIRSTNME
parameters:
- name: job_title
type: string
description: "Job title - Select from common job titles"
required: true
enum: ["MANAGER", "ANALYST", "DESIGNER", "CLERK", "SALESREP", "PRES"]
```
</Tab>
</Tabs>
<Note>
**Enum Parameters**: Enum parameters automatically enhance descriptions for LLMs: "Must be one of: 'A00', 'B01', 'C01'...". This provides autocomplete-like guidance and prevents invalid queries. Use enums whenever you have a fixed set of valid values.
</Note>
---
### Tool 4: Boolean Parameters
**Tool:** `get_employee_projects`
**Demonstrates:** Boolean flags for conditional filtering, complex multi-table joins
```yaml
get_employee_projects:
source: ibmi-sample
description: List projects an employee is working on
statement: |
SELECT
P.PROJNO,
P.PROJNAME,
A.ACTNO,
A.ACTDESC,
EPA.EMSTDATE AS START_DATE,
EPA.EMENDATE AS END_DATE,
EPA.EMPTIME
FROM SAMPLE.EMPPROJACT EPA
JOIN SAMPLE.PROJECT P ON EPA.PROJNO = P.PROJNO
JOIN SAMPLE.PROJACT PA ON EPA.PROJNO = PA.PROJNO AND EPA.ACTNO = PA.ACTNO
JOIN SAMPLE.ACT A ON EPA.ACTNO = A.ACTNO
WHERE EPA.EMPNO = :employee_id
AND (:include_completed = 1 OR EPA.EMENDATE IS NULL)
ORDER BY EPA.EMSTDATE DESC
parameters:
- name: employee_id
type: string
description: "Employee ID (e.g., '000010') - Must be 6 digits"
required: true
pattern: "^[0-9]{6}$"
- name: include_completed
type: boolean
description: "Include completed projects (true) or only active projects (false)"
default: true
```
**Key Techniques:**
- **Boolean in SQL:** `:include_completed = 1` (true) or `= 0` (false)
- **Conditional filtering:** `(:include_completed = 1 OR EPA.EMENDATE IS NULL)` filters active projects when false
- **4-table joins:** Connects employee project activities with projects, project activities, and activity descriptions
- **Default value:** Makes parameter optional (defaults to showing all projects)
**Usage Examples:**
```json
// Get all projects (completed and active)
{
"name": "get_employee_projects",
"arguments": {
"employee_id": "000010",
"include_completed": true
}
}
// Get only active projects
{
"name": "get_employee_projects",
"arguments": {
"employee_id": "000010",
"include_completed": false
}
}
```
---
### Tool 5: Integer Parameters with Aggregations
**Tool:** `get_department_salary_stats`
**Demonstrates:** Multiple optional integers, default values, SQL aggregations
```yaml
get_department_salary_stats:
source: ibmi-sample
description: Salary statistics by department with optional salary range filter
statement: |
SELECT
D.DEPTNO,
D.DEPTNAME,
COUNT(E.EMPNO) AS EMPLOYEE_COUNT,
AVG(E.SALARY) AS AVG_SALARY,
MIN(E.SALARY) AS MIN_SALARY,
MAX(E.SALARY) AS MAX_SALARY,
SUM(E.SALARY) AS TOTAL_SALARY
FROM SAMPLE.DEPARTMENT D
LEFT JOIN SAMPLE.EMPLOYEE E ON D.DEPTNO = E.WORKDEPT
WHERE (D.DEPTNO = :department_id OR :department_id = '*ALL')
AND (E.SALARY >= :min_salary OR :min_salary IS NULL)
AND (E.SALARY <= :max_salary OR :max_salary IS NULL)
GROUP BY D.DEPTNO, D.DEPTNAME
ORDER BY D.DEPTNO
parameters:
- name: department_id
type: string
description: "Department ID (e.g., 'A00') or '*ALL' for all departments"
default: "*ALL"
- name: min_salary
type: integer
description: "Minimum salary filter"
min: 0
max: 100000
default: 0
- name: max_salary
type: integer
description: "Maximum salary filter"
min: 0
max: 100000
default: 100000
```
**Key Techniques:**
- **Integer constraints:** `min: 0`, `max: 100000` prevent invalid salary ranges
- **Aggregation functions:** COUNT, AVG, MIN, MAX, SUM provide statistical summaries
- **GROUP BY:** Groups results by department for aggregate calculations
- **Special value pattern:** `'*ALL'` provides "all departments" option
- **NULL handling:** `OR :min_salary IS NULL` allows optional filtering
<Note>
**Default Values**: Integer parameters with default values don't need `required: false`. The presence of a default makes them optional automatically. This pattern works for all parameter types.
</Note>
---
### Tool 6: Array Parameters
**Tool:** `find_project_team_members`
**Demonstrates:** Array parameters with SQL IN clauses, array length constraints
```yaml
find_project_team_members:
source: ibmi-sample
description: Find all employees working on specific projects
statement: |
SELECT
E.EMPNO,
E.FIRSTNME,
E.MIDINIT,
E.LASTNAME,
E.JOB,
E.WORKDEPT,
D.DEPTNAME,
EPA.PROJNO,
EPA.EMSTDATE AS PROJECT_START_DATE,
EPA.EMENDATE AS PROJECT_END_DATE,
EPA.EMPTIME AS TIME_ALLOCATION
FROM SAMPLE.EMPPROJACT EPA
JOIN SAMPLE.EMPLOYEE E ON EPA.EMPNO = E.EMPNO
LEFT JOIN SAMPLE.DEPARTMENT D ON E.WORKDEPT = D.DEPTNO
WHERE EPA.PROJNO IN (:project_ids)
ORDER BY EPA.PROJNO, E.LASTNAME, E.FIRSTNME
parameters:
- name: project_ids
type: array
itemType: string
description: "List of project IDs to search for (e.g., ['MA2100', 'AD3100'])"
required: true
minLength: 1
maxLength: 10
```
**Key Techniques:**
- **Array expansion:** `IN (:project_ids)` automatically expands to `IN (?, ?, ?)` with safe parameter binding
- **itemType:** Specifies that array contains strings (also supports integer, float, boolean)
- **Length constraints:** `minLength: 1` ensures at least one ID, `maxLength: 10` prevents overly broad queries
- **Example in description:** Guides LLM on correct JSON array format
**MCP Tool Call:**
```json
{
"name": "find_project_team_members",
"arguments": {
"project_ids": ["MA2100", "AD3100", "PL2100"]
}
}
```
<Warning>
**Array Input Format:** Arrays must be passed as **JSON arrays**, not strings:
- ✅ Correct: `{"project_ids": ["MA2100", "AD3100"]}`
- ❌ Incorrect: `{"project_ids": "('MA2100', 'AD3100')"}`
</Warning>
---
### Tool 7: Float Parameters
**Tool:** `calculate_employee_bonus`
**Demonstrates:** Float parameters for decimal calculations, mathematical operations
```yaml
calculate_employee_bonus:
source: ibmi-sample
description: Calculate potential bonus for an employee based on performance rating
statement: |
SELECT
E.EMPNO,
E.FIRSTNME,
E.LASTNAME,
E.SALARY,
E.SALARY * :performance_multiplier AS CALCULATED_BONUS
FROM SAMPLE.EMPLOYEE E
WHERE E.EMPNO = :employee_id
parameters:
- name: employee_id
type: string
description: "Employee ID (e.g., '000010')"
required: true
pattern: "^[0-9]{6}$"
- name: performance_multiplier
type: float
description: "Performance rating multiplier (0.0-0.3)"
required: true
min: 0.0
max: 0.3
default: 0.1
```
**Key Techniques:**
- **Float type:** Allows decimal values (0.1, 0.15, 0.25, etc.)
- **Range constraints:** `min: 0.0`, `max: 0.3` limits multiplier to 0-30%
- **SQL arithmetic:** `E.SALARY * :performance_multiplier` performs calculation
- **Combined parameters:** String pattern + float calculation in single tool
**Usage:**
```json
// 10% bonus (default)
{
"name": "calculate_employee_bonus",
"arguments": {
"employee_id": "000010",
"performance_multiplier": 0.1
}
}
// 25% bonus
{
"name": "calculate_employee_bonus",
"arguments": {
"employee_id": "000010",
"performance_multiplier": 0.25
}
}
```
---
### Tool 8: Pagination with Multiple Parameters
**Tool:** `search_employees`
**Demonstrates:** LIMIT/OFFSET pagination, case-insensitive search, partial matching
```yaml
search_employees:
source: ibmi-sample
description: Search for employees by name with pagination
statement: |
SELECT
E.EMPNO,
E.FIRSTNME,
E.MIDINIT,
E.LASTNAME,
E.JOB,
E.WORKDEPT,
D.DEPTNAME
FROM SAMPLE.EMPLOYEE E
LEFT JOIN SAMPLE.DEPARTMENT D ON E.WORKDEPT = D.DEPTNO
WHERE UPPER(E.FIRSTNME) LIKE UPPER('%' || :name_search || '%')
OR UPPER(E.LASTNAME) LIKE UPPER('%' || :name_search || '%')
ORDER BY E.LASTNAME, E.FIRSTNME
LIMIT :page_size OFFSET (:page_number - 1) * :page_size
parameters:
- name: name_search
type: string
description: "Name to search for (partial match)"
required: true
minLength: 2
- name: page_size
type: integer
description: "Number of results per page"
default: 10
min: 1
max: 100
- name: page_number
type: integer
description: "Page number (starting from 1)"
default: 1
min: 1
```
**Key Techniques:**
- **minLength:** `minLength: 2` prevents single-character searches that return too many results
- **Pagination pattern:** `LIMIT :page_size OFFSET (:page_number - 1) * :page_size`
- **Case-insensitive search:** `UPPER(column) LIKE UPPER(pattern)`
- **Partial matching:** `'%' || :name_search || '%'` finds names containing the search term
- **Multiple integer parameters:** page_size and page_number with sensible defaults
**Usage:**
```json
// First page of results
{
"name": "search_employees",
"arguments": {
"name_search": "Smith",
"page_size": 10,
"page_number": 1
}
}
// Second page with custom size
{
"name": "search_employees",
"arguments": {
"name_search": "JO",
"page_size": 25,
"page_number": 2
}
}
```
---
### Toolset Organization
The file defines 3 toolsets to organize the 8 tools by functional area:
```yaml
toolsets:
employee_information:
title: "Employee Information"
description: "Tools for retrieving and analyzing employee data"
tools:
- get_employee_details
- find_employees_by_department
- find_employees_by_job
- search_employees
project_management:
title: "Project Management"
description: "Tools for managing project assignments and team members"
tools:
- get_employee_projects
- find_project_team_members
salary_analysis:
title: "Salary Analysis"
description: "Tools for analyzing salary data across departments"
tools:
- get_department_salary_stats
- calculate_employee_bonus
```
<Note>
**Selective Loading**: Toolsets enable selective loading. Load only what you need:
- `--toolsets employee_information` loads just employee lookup tools
- `--toolsets employee_information,salary_analysis` loads two categories
- Omit `--toolsets` to load everything
This improves startup time and reduces API surface for focused agents.
</Note>
---
### Running the Example
**List available toolsets:**
```bash
npx -y @ibm/ibmi-mcp-server@latest --list-toolsets --tools tools/sample/employee-info.yaml
```
**Start server with specific toolsets:**
```bash
# Load only employee information tools
npx -y @ibm/ibmi-mcp-server@latest --tools tools/sample/employee-info.yaml --toolsets employee_information
# Load multiple toolsets
npx -y @ibm/ibmi-mcp-server@latest --tools tools/sample/employee-info.yaml --toolsets employee_information,salary_analysis
# Load entire directory (all sample tools)
npx -y @ibm/ibmi-mcp-server@latest --tools tools/sample
```
---
### Parameter Type Summary
This example demonstrates all five parameter types across eight tools:
| Tool | String | Integer | Float | Boolean | Array |
|------|--------|---------|-------|---------|-------|
| `get_employee_details` | ✅ (pattern) | | | | |
| `find_employees_by_department` | ✅ (enum) | | | | |
| `find_employees_by_job` | ✅ (enum) | | | | |
| `get_employee_projects` | ✅ (pattern) | | | ✅ | |
| `get_department_salary_stats` | ✅ (default) | ✅ (optional) | | | |
| `find_project_team_members` | | | | | ✅ |
| `calculate_employee_bonus` | ✅ (pattern) | | ✅ | | |
| `search_employees` | ✅ (minLength) | ✅ (pagination) | | | |
### SQL Techniques Demonstrated
This file also showcases essential SQL patterns for IBM i development:
<CardGroup cols={2}>
<Card title="Joins" icon="link">
- **INNER JOIN:** Connecting related tables
- **LEFT JOIN:** Handling optional relationships
- **Self-join:** Hierarchical data (manager lookup)
- **Multi-table joins:** 4-way joins for complex data
</Card>
<Card title="Aggregations" icon="chart-column">
- **COUNT:** Counting records
- **AVG, MIN, MAX, SUM:** Statistical calculations
- **GROUP BY:** Grouping for aggregates
</Card>
<Card title="Filtering" icon="filter">
- **WHERE clauses:** Basic and conditional filtering
- **IN clauses:** Array-based filtering
- **NULL handling:** Optional parameter patterns
- **Special values:** `*ALL` pattern for "all records"
</Card>
<Card title="Search & Pagination" icon="magnifying-glass">
- **LIKE with wildcards:** Partial matching
- **UPPER():** Case-insensitive search
- **LIMIT/OFFSET:** Pagination pattern
- **ORDER BY:** Sorting results
</Card>
</CardGroup>
<Success>
**Complete Reference Implementation**: This file serves as a comprehensive template for building production-ready IBM i MCP tools. Use it as a starting point for your own tool development, adapting the patterns to your specific database schema and business requirements.
</Success>
---
## Common IBM i Patterns
Here are proven patterns for working with IBM i system services:
### System Information Queries
```yaml
tools:
system_overview:
source: ibmi-system
description: "Comprehensive system status and configuration"
statement: |
SELECT
system_name,
current_timestamp,
elapsed_time,
total_jobs,
active_threads,
cpu_utilization,
main_storage_size / 1024 / 1024 AS memory_gb,
current_unprotected_used / 1024 / 1024 AS used_memory_gb
FROM TABLE(QSYS2.SYSTEM_STATUS()) X
subsystem_status:
source: ibmi-system
description: "Status of all subsystems"
statement: |
SELECT subsystem_name, subsystem_library, status,
monitor_job, secondary_language,
COALESCE(current_active_jobs, 0) as active_jobs,
COALESCE(maximum_active_jobs, 0) as max_jobs
FROM qsys2.subsystem_info
ORDER BY subsystem_name
```
### Library and Object Management
```yaml
tools:
library_objects:
source: ibmi-system
description: "List objects in a library with optional type filtering"
parameters:
- name: library
type: string
required: true
pattern: "^[A-Z][A-Z0-9_]*$"
description: "Library name to examine"
- name: object_type
type: string
required: false
enum: ["*FILE", "*PGM", "*SRVPGM", "*DTAARA", "*USRSPC"]
description: "Object type filter (optional)"
statement: |
SELECT object_name, object_type, object_size,
created_timestamp, last_used_timestamp,
object_owner, authorization_list
FROM table(qsys2.object_statistics(:library,
COALESCE(:object_type, '*ALL'))) x
ORDER BY object_name
library_list:
source: ibmi-system
description: "Show current library list for analysis"
statement: |
SELECT ordinal_position, library_name, library_type,
library_text_description
FROM qsys2.library_list_info
ORDER BY ordinal_position
```
### Database Analysis
```yaml
tools:
table_analysis:
source: ibmi-system
description: "Analyze table structure and statistics"
parameters:
- name: schema
type: string
required: true
description: "Schema (library) name"
- name: table_name
type: string
required: true
description: "Table name to analyze"
statement: |
SELECT
t.table_name,
t.table_type,
t.number_rows,
t.create_timestamp,
c.column_name,
c.ordinal_position,
c.data_type,
c.column_size,
c.is_nullable,
c.column_default
FROM qsys2.systables t
JOIN qsys2.syscolumns c ON t.table_schema = c.table_schema
AND t.table_name = c.table_name
WHERE t.table_schema = UPPER(:schema)
AND t.table_name = UPPER(:table_name)
ORDER BY c.ordinal_position
foreign_key_relationships:
source: ibmi-system
description: "Find foreign key relationships for a table"
parameters:
- name: schema
type: string
required: true
- name: table_name
type: string
required: true
statement: |
SELECT
fk.constraint_name,
fk.table_schema AS fk_schema,
fk.table_name AS fk_table,
fk.column_name AS fk_column,
pk.table_schema AS pk_schema,
pk.table_name AS pk_table,
pk.column_name AS pk_column
FROM qsys2.syskeycst fk
JOIN qsys2.sysrefcst r ON fk.constraint_name = r.constraint_name
JOIN qsys2.syskeycst pk ON r.unique_constraint_name = pk.constraint_name
WHERE fk.table_schema = UPPER(:schema)
AND fk.table_name = UPPER(:table_name)
ORDER BY fk.constraint_name, fk.ordinal_position
```
## Advanced Features
### Response Formatting
Control how results are presented to AI agents:
```yaml
tools:
formatted_system_report:
source: ibmi-system
description: "System report with markdown formatting"
responseFormat: markdown
statement: |
SELECT
'# System Status Report' AS report_header,
'## Current Time: ' || CURRENT_TIMESTAMP AS timestamp_section,
'### CPU Utilization: ' || cpu_utilization || '%' AS cpu_info,
'### Memory Usage: ' ||
ROUND((current_unprotected_used * 100.0 / main_storage_size), 2) ||
'%' AS memory_info
FROM TABLE(QSYS2.SYSTEM_STATUS()) X
```
### Security Configuration
Mark sensitive operations for audit logging and access control:
```yaml
tools:
sensitive_user_info:
source: ibmi-system
description: "User profile information (requires authority)"
security:
audit: true
scopes: ["user:read"]
readOnly: true
parameters:
- name: user_profile
type: string
required: true
pattern: "^[A-Z][A-Z0-9_]*$"
statement: |
SELECT user_profile_name, status, previous_signon,
days_until_password_expires, user_class_name
FROM qsys2.user_info
WHERE user_profile_name = :user_profile
privileged_system_config:
source: ibmi-system
description: "System configuration requiring special authority"
security:
audit: true
requiredAuthority: "*ALLOBJ"
warning: "Requires *ALLOBJ special authority"
statement: |
SELECT * FROM qsys2.system_value_info
WHERE system_value_name LIKE 'Q%SEC%'
```
### Error Handling and Validation
Build robust tools with comprehensive error handling:
```yaml
tools:
validated_object_query:
source: ibmi-system
description: "Query objects with comprehensive validation"
parameters:
- name: library
type: string
required: true
pattern: "^[A-Z][A-Z0-9_]*$"
maxLength: 10
description: "Library name (must exist and be accessible)"
- name: object_filter
type: string
required: false
pattern: "^[A-Z*][A-Z0-9_*]*$"
maxLength: 10
description: "Object name filter (supports * wildcards)"
statement: |
WITH library_check AS (
SELECT library_name
FROM qsys2.library_info
WHERE library_name = :library
),
object_list AS (
SELECT o.*, l.library_name
FROM library_check l,
table(qsys2.object_statistics(l.library_name,
COALESCE(:object_filter, '*ALL'))) o
)
SELECT
CASE
WHEN NOT EXISTS(SELECT 1 FROM library_check)
THEN 'ERROR: Library ' || :library || ' not found or not accessible'
ELSE object_name
END AS result,
object_type,
object_size,
created_timestamp
FROM object_list
UNION ALL
SELECT
'ERROR: Library ' || :library || ' not found or not accessible',
NULL, NULL, NULL
FROM library_check
WHERE NOT EXISTS(SELECT 1 FROM library_check)
ORDER BY result
```
## Testing and Debugging
### Validation Commands
Test your YAML configuration before deployment:
```bash
# Validate YAML syntax and structure
npm run validate -- --config my-tools.yaml
# List available toolsets
npm run start:http -- --list-toolsets --tools my-tools.yaml
# Test specific tool execution
npm run test -- --grep "yaml-sql"
```
<Note>
For complete testing strategies including MCP Inspector usage, see the [Quick Start Guide](/quickstart#step-4-test-with-mcp-inspector-5-minutes). For production testing, refer to the [Production Deployment](/deployment/production) guide.
</Note>
### Debug Mode
Enable debug logging to troubleshoot tool execution:
```bash
MCP_LOG_LEVEL=debug TOOLS_YAML_PATH=my-tools.yaml npm run start:http
```
### Common Issues and Solutions
<AccordionGroup>
<Accordion title="Parameter Binding Errors" icon="exclamation-triangle">
**Problem**: `Parameter :parameter_name not found in statement`
**Solution**: Ensure parameter names in the `statement` match exactly with parameter definitions:
```yaml
# ❌ Mismatch
parameters:
- name: user_name
statement: "WHERE user = :username" # Wrong parameter name
# ✅ Correct
parameters:
- name: user_name
statement: "WHERE user = :user_name" # Matching parameter name
```
</Accordion>
<Accordion title="SQL Syntax Errors" icon="code">
**Problem**: SQL statement fails to execute
**Solution**: Test SQL separately in a DB2 client first:
```bash
# Test in IBM i ACS or other SQL client
SELECT * FROM qsys2.active_job_info
WHERE user_name = 'TESTUSER'
FETCH FIRST 10 ROWS ONLY;
```
</Accordion>
<Accordion title="Authority Issues" icon="lock">
**Problem**: `SQL0551: Not authorized to object`
**Solution**: Verify user has appropriate authorities:
```sql
-- Check object authorities
SELECT * FROM qsys2.object_privileges
WHERE object_schema = 'QSYS2'
AND object_name = 'ACTIVE_JOB_INFO'
AND grantee = 'YOUR_USER';
```
</Accordion>
<Accordion title="Connection Issues" icon="wifi">
**Problem**: Cannot connect to IBM i system
**Solution**: Verify connection parameters and Mapepire daemon:
```bash
# Check if Mapepire daemon is running
ping your-ibmi-host
telnet your-ibmi-host 8076
```
</Accordion>
</AccordionGroup>
## File Organization Best Practices
### Single Domain Approach
Organize tools by business domain or functional area:
```
my-tools/
├── performance.yaml # System performance monitoring
├── security.yaml # Security and audit tools
├── business.yaml # Business logic and reporting
└── development.yaml # Development and testing tools
```
### Multi-Environment Support
Use environment-specific configurations:
```yaml
# environments/production.yaml
sources:
production:
host: ${PROD_DB2i_HOST}
user: ${PROD_DB2i_USER}
password: ${PROD_DB2i_PASS}
port: 8076
ignore-unauthorized: false
# environments/development.yaml
sources:
development:
host: ${DEV_DB2i_HOST}
user: ${DEV_DB2i_USER}
password: ${DEV_DB2i_PASS}
port: 8076
ignore-unauthorized: true
```
### Version Control
Include metadata for tool versioning and maintenance:
```yaml
metadata:
version: "2.1.0"
description: "Production monitoring tools for IBM i"
author: "IT Operations Team"
created: "2024-01-15"
lastUpdated: "2024-01-20"
keywords: ["monitoring", "performance", "production"]
```
## Performance Considerations
### Query Optimization
Always include appropriate performance optimizations:
```yaml
# ✅ Good: Row limiting and proper indexing
statement: |
SELECT job_name, user_name, cpu_used
FROM qsys2.active_job_info
WHERE user_name = :user_name
ORDER BY cpu_used DESC
FETCH FIRST 100 ROWS ONLY
# ❌ Avoid: Unlimited results
statement: |
SELECT * FROM qsys2.active_job_info
WHERE user_name = :user_name
```
### Connection Pooling
The MCP server automatically manages connection pooling, but you can optimize usage:
```yaml
# Use consistent source names for better pooling
sources:
primary-system: # Consistent naming
host: ${DB2i_HOST}
# ... connection details
tools:
tool1:
source: primary-system # Reuses connection
tool2:
source: primary-system # Reuses connection
```
## Next Steps
<CardGroup cols={2}>
<Card title="Testing Guide" icon="flask" href="/sql-tools/testing">
Learn how to test and debug your SQL tools effectively
</Card>
<Card title="Examples & Patterns" icon="lightbulb" href="/sql-tools/examples">
Explore real-world examples and advanced patterns
</Card>
<Card title="Agent Integration" icon="robot" href="/agents/building-agents">
Build AI agents that use your custom SQL tools
</Card>
<Card title="Production Deployment" icon="server" href="/deployment/production">
Deploy your tools to production with monitoring
</Card>
</CardGroup>
<Note>
**Tool Design Philosophy**: Effective SQL tools balance three concerns: **usability** (clear parameters and descriptions for AI agents), **security** (proper validation and authority checking), and **performance** (efficient queries that respect system resources). Start simple and add complexity incrementally as you understand your specific use cases.
</Note>