describe_table
Get the structure of a database table
LABSCO SUMMARY
Reads a database the way a careful analyst would: schema first, then rows.
The schema tools are the reason to reach for this rather than a bare SQL socket — constraints, indexes, views and function listings give a model enough to write a correct join instead of guessing at column names. Pagination, a query timeout and a read-only default keep an exploratory session from becoming an incident.
What it is
A PostgreSQL MCP server built on Kysely, aimed at letting a client read a live database safely. Queries are parameterized and paginated; alongside them sits a full schema-inspection surface — tables, columns, constraints, indexes, views, functions and table statistics — plus EXPLAIN for a plan without running the statement. READ_ONLY defaults to on, restricting execution to SELECT, WITH and EXPLAIN.
What you get
- SQL executed with bound parameters and page-size and offset handling, up to 500 rows per page —
query - A query's execution plan without running it, optionally with
ANALYZE, in text, json, xml or yaml —explain_query - A table's structure and column detail, and its constraints including primary and foreign keys —
describe_table,get_constraints - The schemas in the database and the tables in a schema, with system schemas excluded unless you ask for them —
list_schemas,list_tables - Indexes for a table or a whole schema, so a slow query can be read against what is actually indexed —
list_indexes - Views, and the functions and stored procedures in a schema —
list_views,list_functions - Table size and statistics for one table or the whole schema —
get_table_stats
Requirements
Credentials for a PostgreSQL database, passed as environment variables: DB_HOST, DB_PORT (5432), DB_USER, DB_PASSWORD, DB_NAME and DB_SSL. The package is @abiswas97/postgres-mcp 2.0.0 with a postgres-mcp binary, run over stdio. READ_ONLY is true unless you change it, which is the setting that decides whether an agent can write to this database at all — leave it on for anything you care about. QUERY_TIMEOUT cuts a statement off at 30000 milliseconds, MAX_PAGE_SIZE caps a page at 500 rows and DEFAULT_PAGE_SIZE sets 100 when the call does not say.
Setup effort
One command plus credentials — npx @abiswas97/postgres-mcp, then supply credentials
USE CASES
01
Asking a question of a database you don't know
List the schemas and tables, describe the ones that look relevant, read their constraints to find how they join, and only then write the query.
02
Working out why a query is slow
Read the execution plan, then check which indexes actually exist on the tables involved and how large they are before changing anything.
03
Pulling a report out of production without risk
Leave READ_ONLY on so only SELECT, WITH and EXPLAIN run, and let pagination bound the result instead of a forgotten LIMIT.
04
Finding the logic that already lives in the database
List the views and the stored functions in a schema before rewriting business rules that are already implemented there.
10 tools
Counted once with only startup setup. Other versions, modes or optional credentials may expose a different list.
explain_query
Get query execution plan (EXPLAIN)
get_constraints
Get constraints for a table
get_table_stats
Get table statistics and size information
list_functions
List functions and procedures in a schema
list_indexes
List indexes for a table or schema
list_schemas
List all schemas in the database
list_tables
List all tables in a schema
list_views
List views in a schema
query
Execute SQL queries with pagination support and parameterization for security. Supports page sizes up to 500 rows.
BEFORE YOU INSTALL
What to know first
Tools you get
10 tools when we connected.
Requires
- npx on PATH
- DB_PASSWORD in your environment
Where it runs
The documented client runs the server on your machine.
CONTEXT COST
Light Standing cost
Rated by the size of the 10 tool definitions that ride along on every turn, not by how many there are
INSTALLATION
Connect your client
Server setup
TERMINAL
npx @abiswas97/postgres-mcpMCP Clients
Claude Desktop
CLAUDE DESKTOP · JSON
{
"mcpServers": {
"postgres-mcp-server": {
"command": "npx",
"args": [
"@abiswas97/postgres-mcp"
],
"env": {
"DB_HOST": "127.0.0.1",
"DB_PORT": "5432",
"DB_USER": "postgres",
"DB_PASSWORD": "<YOUR_DB_PASSWORD>",
"DB_NAME": "<YOUR_DB_NAME>",
"DB_SSL": "true"
}
}
}
}
