# get_table_schema

Get the schema definition for a specified table.

Agent View of the PolicyLayer registry record for `get_table_schema`. HTML page: https://policylayer.com/tools/aadarshjain-postgres-mcp-server/get-table-schema

## Facts

- Tool: `get_table_schema`
- Server: PostgreSQL MCP Server (`aadarshjain/postgres-mcp-server`) — https://policylayer.com/tools/aadarshjain-postgres-mcp-server.md
- Homepage: https://github.com/aadarshjain/postgres-mcp-server
- Risk category: Read (Low risk)
- Registry record: grade C, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Allowed

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "get_table_schema",
    "arguments": {}
  }
}
```

## Why get_table_schema is rated Low

This tool retrieves structural metadata about a table (column names, types, constraints) without executing code, modifying data, or triggering external operations. It is a pure read operation with no side effects. Severity is low because schema information is typically non-sensitive or already known to users with database access, and misuse cannot alter or destroy data.

From the tool's own definition: "Tool description states 'Get the schema definition for a specified table' — a query operation with no modification or deletion capability."

## Use case

AI agents call get_table_schema to retrieve information from PostgreSQL MCP Server without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

## Recommended policy (PolicyLayer)

Verdict: **Allowed**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches PostgreSQL MCP Server:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "get_table_schema": {}
  }
}
```

## Other tools on PostgreSQL MCP Server (4)

- `execute_query` — Execute — https://policylayer.com/tools/aadarshjain-postgres-mcp-server/execute-query.md
- `filter_instances` — Read — https://policylayer.com/tools/aadarshjain-postgres-mcp-server/filter-instances.md
- `get_database_stats` — Read — https://policylayer.com/tools/aadarshjain-postgres-mcp-server/get-database-stats.md
- `list_tables` — Read — https://policylayer.com/tools/aadarshjain-postgres-mcp-server/list-tables.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=aadarshjain-postgres-mcp-server · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/aadarshjain-postgres-mcp-server