lcbp3/memory/mcp-tools.md

MCP Tools Documentation

MCP MariaDB Tools

MCP MariaDB server provides tools for direct database inspection and management. Used for:

• Verifying schema against spec file specs/03-Data-and-Storage/lcbp3-v1.9.0-schema-02-tables.sql
• Debugging database issues without entering MySQL client
• Checking data in production/staging
• Validating schema changes before deploy

Available Tools

Tool	Purpose	Example Usage
mcp1_mysql_test_connection	Test database connection	Verify MCP server connectivity
mcp1_mysql_show_databases	List all databases	See available databases
mcp1_mysql_show_tables	List all tables in database	See tables in lcbp3
mcp1_mysql_describe_table	View table structure/columns	Check columns, types, keys of correspondences
mcp1_mysql_query	Run SELECT query	View data in table or join query
mcp1_mysql_insert	INSERT data	Add seed data or test data
mcp1_mysql_update	UPDATE data	Modify data in table
mcp1_mysql_delete	DELETE data	Delete data from table

Usage with Development Flow

When writing new queries:

1. Use mcp1_mysql_describe_table to check columns and types
2. Compare with specs/03-Data-and-Storage/lcbp3-v1.9.0-schema-02-tables.sql
3. Use mcp1_mysql_query to test query before implement

When changing schema (ADR-009):

1. Use mcp1_mysql_describe_table to see current structure
2. Create SQL delta in specs/03-Data-and-Storage/deltas/
3. Use mcp1_mysql_query to verify result after apply delta

When debugging database issues:

1. Use mcp1_mysql_query to see actual data
2. Compare with spec and data dictionary
3. Check foreign keys and constraints

Warnings

• ❌ NEVER use MCP MariaDB for DDL operations (CREATE/ALTER/DROP) directly — must use SQL delta per ADR-009
• ✅ Use for DQL/DML operations (SELECT/INSERT/UPDATE/DELETE) for debug and test only
• ⚠️ Be careful with DELETE operations — may lose data in production
• ✅ Always verify schema against spec file before writing queries

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MCP Memory Tools

MCP Memory server provides tools for managing Knowledge Graph and Long-term Memory. Used for:

• Storing project knowledge and context in Graph format (Entities + Relations + Observations)
• Searching and retrieving context from memory saved in previous sessions
• Creating/editing/deleting entities, relations, and observations in knowledge graph

Available Tools

Tool	Purpose	Example Usage
mcp3_create_entities	Create multiple new entities with observations	Create new entities like Project, User, Task
mcp3_create_relations	Create relations between entities	Create relation: Project → has → User
mcp3_add_observations	Add observations to existing entities	Add additional context to entity
mcp3_delete_entities	Delete entities and related relations	Delete unused entities
mcp3_delete_relations	Delete relations between entities	Delete incorrect or unused relations
mcp3_delete_observations	Delete observations from entity	Delete incorrect or stale context
mcp3_open_nodes	Retrieve entities by name	Get specific entity by name
mcp3_read_graph	Read entire knowledge graph	See full graph structure
mcp3_search_nodes	Search entities by query	Find entity by name, type, or observation

Usage with Development Flow

When saving new context:

1. Use mcp3_create_entities to create new entities (if not exist)
2. Use mcp3_create_relations to link entities
3. Use mcp3_add_observations to add context/observations

When searching context:

1. Use mcp3_search_nodes to find relevant entities
2. Use mcp3_open_nodes to get specific entity data
3. Use mcp3_read_graph to see relations between entities

When editing context:

1. Use mcp3_add_observations to add new observations
2. Use mcp3_delete_observations to delete incorrect observations
3. Use mcp3_create_relations or mcp3_delete_relations to adjust relations

Warnings

• ✅ Use for storing context that needs to be shared across multiple sessions — e.g., important decisions, architecture decisions, rollout history
• ⚠️ Be careful when deleting entities — may lose context still in use
• ✅ Check if entity exists before creating — use mcp3_search_nodes or mcp3_open_nodes first
• ✅ Use clear and unique entity names — to prevent confusion