# PostgreSQL_list_roles_with_superuser

List database roles, optionally showing only superusers.

Agent View of the PolicyLayer registry record for `PostgreSQL_list_roles_with_superuser`. HTML page: https://policylayer.com/tools/mukul975-postgres-mcp-server/postgresql-list-roles-with-superuser

## Facts

- Tool: `PostgreSQL_list_roles_with_superuser`
- Server: Postgres (`mukul975/postgres-mcp-server`) — https://policylayer.com/tools/mukul975-postgres-mcp-server.md
- Homepage: https://github.com/mukul975/postgres-mcp-server
- Risk category: Read (Low risk)
- Registry record: grade F, 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": "PostgreSQL_list_roles_with_superuser",
    "arguments": {}
  }
}
```

## Why PostgreSQL_list_roles_with_superuser is rated Low

This tool retrieves role information from PostgreSQL—a read-only operation that queries existing data without side effects. However, severity is elevated to 'medium' rather than 'low' because the data retrieved (superuser role membership) is sensitive security metadata.

From the tool's own definition: "Tool name contains 'list' and description states 'List database roles'; this is a query/retrieval operation with no modification or deletion. The word 'showing' indicates data retrieval."

## Use case

AI agents call PostgreSQL_list_roles_with_superuser to retrieve information from Postgres 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 Postgres:

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

## Other tools on Postgres (238)

- `PostgreSQL_drop_index` — Destructive — https://policylayer.com/tools/mukul975-postgres-mcp-server/postgresql-drop-index.md
- `PostgreSQL_drop_schema` — Destructive — https://policylayer.com/tools/mukul975-postgres-mcp-server/postgresql-drop-schema.md
- `PostgreSQL_drop_user` — Destructive — https://policylayer.com/tools/mukul975-postgres-mcp-server/postgresql-drop-user.md
- `PostgreSQL_analyze_database` — Execute — https://policylayer.com/tools/mukul975-postgres-mcp-server/postgresql-analyze-database.md
- `PostgreSQL_execute_select_query` — Execute — https://policylayer.com/tools/mukul975-postgres-mcp-server/postgresql-execute-select-query.md
- `PostgreSQL_execute_update_query` — Execute — https://policylayer.com/tools/mukul975-postgres-mcp-server/postgresql-execute-update-query.md
- `PostgreSQL_kill_connection` — Execute — https://policylayer.com/tools/mukul975-postgres-mcp-server/postgresql-kill-connection.md
- `PostgreSQL_refresh_materialized_view` — Execute — https://policylayer.com/tools/mukul975-postgres-mcp-server/postgresql-refresh-materialized-view.md
- `PostgreSQL_vacuum_analyze_table` — Execute — https://policylayer.com/tools/mukul975-postgres-mcp-server/postgresql-vacuum-analyze-table.md
- `analyze_buffer_utilization` — Read — https://policylayer.com/tools/mukul975-postgres-mcp-server/analyze-buffer-utilization.md
- `analyze_foreign_key_locks` — Read — https://policylayer.com/tools/mukul975-postgres-mcp-server/analyze-foreign-key-locks.md
- `analyze_index_effectiveness` — Read — https://policylayer.com/tools/mukul975-postgres-mcp-server/analyze-index-effectiveness.md
- `analyze_query_complexity` — Read — https://policylayer.com/tools/mukul975-postgres-mcp-server/analyze-query-complexity.md
- `analyze_query_plans` — Read — https://policylayer.com/tools/mukul975-postgres-mcp-server/analyze-query-plans.md
- `analyze_sequence_usage` — Read — https://policylayer.com/tools/mukul975-postgres-mcp-server/analyze-sequence-usage.md
- `analyze_transaction_wraparound` — Read — https://policylayer.com/tools/mukul975-postgres-mcp-server/analyze-transaction-wraparound.md
- `analyze_trigger_performance` — Read — https://policylayer.com/tools/mukul975-postgres-mcp-server/analyze-trigger-performance.md
- `analyze_vacuum_efficiency` — Read — https://policylayer.com/tools/mukul975-postgres-mcp-server/analyze-vacuum-efficiency.md
- `check_constraint_violations` — Read — https://policylayer.com/tools/mukul975-postgres-mcp-server/check-constraint-violations.md
- `check_database_encoding_collation` — Read — https://policylayer.com/tools/mukul975-postgres-mcp-server/check-database-encoding-collation.md
- `check_function_performance` — Read — https://policylayer.com/tools/mukul975-postgres-mcp-server/check-function-performance.md
- `check_replication_lag_details` — Read — https://policylayer.com/tools/mukul975-postgres-mcp-server/check-replication-lag-details.md
- `check_table_inheritance` — Read — https://policylayer.com/tools/mukul975-postgres-mcp-server/check-table-inheritance.md
- `monitor_autovacuum_progress` — Read — https://policylayer.com/tools/mukul975-postgres-mcp-server/monitor-autovacuum-progress.md
- `monitor_checkpoint_efficiency` — Read — https://policylayer.com/tools/mukul975-postgres-mcp-server/monitor-checkpoint-efficiency.md
- `monitor_connection_patterns` — Read — https://policylayer.com/tools/mukul975-postgres-mcp-server/monitor-connection-patterns.md
- `monitor_materialized_views` — Read — https://policylayer.com/tools/mukul975-postgres-mcp-server/monitor-materialized-views.md
- `monitor_wal_generation_rate` — Read — https://policylayer.com/tools/mukul975-postgres-mcp-server/monitor-wal-generation-rate.md
- `PostgreSQL_active_temp_file_users` — Read — https://policylayer.com/tools/mukul975-postgres-mcp-server/postgresql-active-temp-file-users.md
- `PostgreSQL_analyze_advanced_buffer_usage` — Read — https://policylayer.com/tools/mukul975-postgres-mcp-server/postgresql-analyze-advanced-buffer-usage.md
- …and 208 more: https://policylayer.com/tools/mukul975-postgres-mcp-server.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=mukul975-postgres-mcp-server · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/mukul975-postgres-mcp-server