Tools Reference

cubrid-mcp-server exposes its capabilities as MCP tools, resources, and prompts. Every tool accepts an optional connection argument (see Multi-Connection); omitting it targets the default connection.

Tools

Schema inspection

all_table_names(connection=None)

Lists every user table in the database. System and catalog tables are excluded.

filter_table_names(substring, connection=None)

Case-insensitive substring search over table names. Use this instead of all_table_names when the schema is large.

schema_definitions(table_name, connection=None)

Column-level metadata for one table: column name, type, nullability, default value, and primary-key membership.

describe_table(table_name, connection=None)

Full metadata for one table in a single call — columns, primary key, and indexes. Mirrors the cubrid://schema/{table} resource.

list_indexes(table_name, connection=None)

Indexes defined on a table, with the indexed key columns and flags (unique, reverse).

list_class_hierarchy(connection=None, ...)

CUBRID CLASS inheritance relationships — which tables inherit from which.

Querying

execute_query(sql, connection=None)

Runs read-only SQL (SELECT, SHOW, DESC, DESCRIBE, EXPLAIN, WITH). Output is automatically truncated to respect the model's context window:

• at most CUBRID_MCP_MAX_ROWS rows (default 1000),
• rendered output capped at CUBRID_MCP_MAX_CHARS characters (default 4000),
• statement length capped at CUBRID_MCP_MAX_SQL_LENGTH (default 65536),
• per-statement socket read timeout of CUBRID_MCP_QUERY_TIMEOUT seconds (default 30).

Multi-statement input is rejected. Binary values are base64-encoded when small and summarized (<binary N bytes>) when large.

explain_query(sql, connection=None)

Returns the execution plan/trace for a SELECT or WITH statement via CUBRID SHOW TRACE. Always read-only, independent of the CUBRID_MCP_READONLY flag.

table_row_counts(connection=None, ...)

COUNT(*) for one table or many — cheaper than sampling rows to estimate size.

CUBRID specifics

list_serials(connection=None)

CUBRID SERIAL sequences with their current value, minimum, maximum, and increment.

health_check(connection=None)

Verifies database connectivity on demand and reports per-connection status. Useful after environment changes or long idle periods.

Opt-in writes

execute_write(sql, connection=None)

Runs a single INSERT, UPDATE, or DELETE statement in an explicit transaction (commit on success, rollback on any failure). Registered only when write mode is enabled (CUBRID_MCP_WRITE=1 or CUBRID_<NAME>_MCP_WRITE=1 on any connection) — with write mode off, the tool does not exist in MCP capability discovery at all.

Constraints: DDL (CREATE/ALTER/DROP/TRUNCATE), standalone reads, transaction control, and multi-statement input are rejected. See the Security Model.

Resources

Schema metadata is also exposed as read-only MCP Resources, so clients can discover schema context without a tool call. Resources reuse the same read-only catalog queries — no additional data-access surface.

Resource URI	Description
cubrid://schema	Whole-schema index: every user table with its per-table resource URI
cubrid://schema/{table}	Per-table metadata (columns, primary key, indexes) — mirrors describe_table

Both return application/json. Table names in {table} are percent-decoded by URI-template matching; an unknown or system table produces a resource-read error, matching the describe_table tool.

Prompts

The server exposes MCP Prompt templates — guidance-only starting points for common inspection tasks. Each prompt returns text telling the client which read-only tools to call and in what order. Prompts never touch the database, execute SQL, or add any data-access surface, and arguments are fenced as untrusted data.

Prompt	Arguments	Description
summarize_table	table	Describe a table, then sample it with a bounded read-only query
explain_query	sql	Obtain and interpret a SELECT/WITH execution plan via explain_query
inspect_schema	(none)	Build a high-level overview of the whole schema from the read-only tools
find_index_candidates	table	Review a table's index coverage for potential review areas