mcp-snowflake-server: Skill for Claude Code

Snowflake Integration Testing

When to Use

• Verifying MCP Snowflake server connectivity after configuration changes
• Testing that MCP tools (list_databases, list_schemas, list_tables, describe_table, read_query) work correctly
• Exploring Snowflake schemas to validate data access permissions
• Discovering tables with specific column data types (VARIANT, OBJECT, ARRAY)
• Sampling rows to verify data shape, nested JSON structure, and content
• Validating Docker or local MCP server deployments

Available MCP Tools

Tool	Purpose
list_databases	List all accessible databases
list_schemas	List schemas in a database
list_tables	List tables in a database.schema
describe_table	Get column metadata for a fully-qualified table
read_query	Execute a read-only SQL query

Procedure

1. Connectivity Check

Verify the connection is active and inspect the session context:

SELECT CURRENT_USER(), CURRENT_ROLE(), CURRENT_WAREHOUSE(), CURRENT_DATABASE(), CURRENT_SCHEMA()

Use read_query to execute this. Confirm user, role, warehouse, database, and schema are as expected.

2. Schema Exploration

Follow this sequence to explore the data landscape:

1. Call list_databases — note accessible databases
2. Pick a target database, call list_schemas with database parameter
3. Pick a target schema, call list_tables with database and schema parameters
4. For specific tables, call describe_table with fully-qualified name (database.schema.table)

3. Data Type Discovery

Find tables with specific column types using read_query:

-- Find OBJECT columns (nested JSON)
SELECT table_schema, table_name, column_name, data_type
FROM <DATABASE>.information_schema.columns
WHERE data_type = 'OBJECT'
LIMIT 20

-- Find VARIANT columns
SELECT table_schema, table_name, column_name, data_type
FROM <DATABASE>.information_schema.columns
WHERE data_type = 'VARIANT'
LIMIT 20

-- Find ARRAY columns
SELECT table_schema, table_name, column_name, data_type
FROM <DATABASE>.information_schema.columns
WHERE data_type = 'ARRAY'
LIMIT 20