# explain_query

A read tool on the Mcpg MCP server.

Agent View of the PolicyLayer registry record for `explain_query`. HTML page: https://policylayer.com/tools/io-github-devopam-mcpg/explain-query

## Facts

- Tool: `explain_query`
- Server: Mcpg (`pypi:mcpg`) — https://policylayer.com/tools/io-github-devopam-mcpg.md
- Install: `npx -y pypi:mcpg`
- Homepage: https://github.com/devopam/MCPg
- 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": "explain_query",
    "arguments": {}
  }
}
```

## Why explain_query is rated Low

EXPLAIN/query explanation is a read-only operation that retrieves and displays query execution plans without modifying, executing, or deleting data. The empty description reduces confidence slightly, but the function name and context of sibling tools strongly suggest diagnostic/analysis purpose typical of PostgreSQL EXPLAIN commands.

From the tool's own definition: "Tool name 'explain_query' indicates query plan analysis/explanation functionality. The sibling tools on this PostgreSQL MCP server include other analysis tools like 'analyze_query_plan', 'analyze_lock_hotspots', and similar read-only diagnostic operations."

## Use case

AI agents call explain_query to retrieve information from Mcpg 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 Mcpg:

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

## Other tools on Mcpg (251)

- `cancel_migration` — Destructive — https://policylayer.com/tools/io-github-devopam-mcpg/cancel-migration.md
- `drop_graph` — Destructive — https://policylayer.com/tools/io-github-devopam-mcpg/drop-graph.md
- `drop_property_graph` — Destructive — https://policylayer.com/tools/io-github-devopam-mcpg/drop-property-graph.md
- `drop_publication` — Destructive — https://policylayer.com/tools/io-github-devopam-mcpg/drop-publication.md
- `drop_subscription` — Destructive — https://policylayer.com/tools/io-github-devopam-mcpg/drop-subscription.md
- `dump_database` — Destructive — https://policylayer.com/tools/io-github-devopam-mcpg/dump-database.md
- `partman_drop_partition` — Destructive — https://policylayer.com/tools/io-github-devopam-mcpg/partman-drop-partition.md
- `prune_audit_events` — Destructive — https://policylayer.com/tools/io-github-devopam-mcpg/prune-audit-events.md
- `restore_database` — Destructive — https://policylayer.com/tools/io-github-devopam-mcpg/restore-database.md
- `cancel_query` — Execute — https://policylayer.com/tools/io-github-devopam-mcpg/cancel-query.md
- `cluster_vectors` — Execute — https://policylayer.com/tools/io-github-devopam-mcpg/cluster-vectors.md
- `complete_migration` — Execute — https://policylayer.com/tools/io-github-devopam-mcpg/complete-migration.md
- `dry_run_ddl` — Execute — https://policylayer.com/tools/io-github-devopam-mcpg/dry-run-ddl.md
- `enable_extension` — Execute — https://policylayer.com/tools/io-github-devopam-mcpg/enable-extension.md
- `enable_logical_replication_on_demand` — Execute — https://policylayer.com/tools/io-github-devopam-mcpg/enable-logical-replication-on-demand.md
- `enable_redis_fdw` — Execute — https://policylayer.com/tools/io-github-devopam-mcpg/enable-redis-fdw.md
- `generate_graph_projection` — Execute — https://policylayer.com/tools/io-github-devopam-mcpg/generate-graph-projection.md
- `generate_test_data` — Execute — https://policylayer.com/tools/io-github-devopam-mcpg/generate-test-data.md
- `hybrid_search` — Execute — https://policylayer.com/tools/io-github-devopam-mcpg/hybrid-search.md
- `maintain_turboquant_index` — Execute — https://policylayer.com/tools/io-github-devopam-mcpg/maintain-turboquant-index.md
- `mmr_search` — Execute — https://policylayer.com/tools/io-github-devopam-mcpg/mmr-search.md
- `open_cursor` — Execute — https://policylayer.com/tools/io-github-devopam-mcpg/open-cursor.md
- `optimize_query` — Execute — https://policylayer.com/tools/io-github-devopam-mcpg/optimize-query.md
- `partman_run_maintenance` — Execute — https://policylayer.com/tools/io-github-devopam-mcpg/partman-run-maintenance.md
- `pg_search_run` — Execute — https://policylayer.com/tools/io-github-devopam-mcpg/pg-search-run.md
- `prepare_migration` — Execute — https://policylayer.com/tools/io-github-devopam-mcpg/prepare-migration.md
- `prewarm_recommended` — Execute — https://policylayer.com/tools/io-github-devopam-mcpg/prewarm-recommended.md
- `prewarm_relation` — Execute — https://policylayer.com/tools/io-github-devopam-mcpg/prewarm-relation.md
- `recommend_redistribute` — Execute — https://policylayer.com/tools/io-github-devopam-mcpg/recommend-redistribute.md
- `reindex_pg_search_index` — Execute — https://policylayer.com/tools/io-github-devopam-mcpg/reindex-pg-search-index.md
- …and 221 more: https://policylayer.com/tools/io-github-devopam-mcpg.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=io-github-devopam-mcpg · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/io-github-devopam-mcpg