# read_pg_buffercache_relations

A read tool on the Mcpg MCP server.

Agent View of the PolicyLayer registry record for `read_pg_buffercache_relations`. HTML page: https://policylayer.com/tools/io-github-devopam-mcpg/read-pg-buffercache-relations

## Facts

- Tool: `read_pg_buffercache_relations`
- 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": "read_pg_buffercache_relations",
    "arguments": {}
  }
}
```

## Why read_pg_buffercache_relations is rated Low

This tool retrieves diagnostic information about PostgreSQL's buffer cache (an internal memory structure tracking page access). No side effects are described or implied. The empty description reduces confidence slightly, but the naming convention strongly suggests a read-only operation that queries system state. Buffer cache information is diagnostic metadata, not sensitive user data, keeping severity low.

From the tool's own definition: "Tool name 'read_pg_buffercache_relations' indicates reading buffer cache relation metadata. The 'read_' prefix and '_relations' suffix suggest querying PostgreSQL's internal buffer cache state without modification."

## Use case

AI agents call read_pg_buffercache_relations 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": {
    "read_pg_buffercache_relations": {}
  }
}
```

## 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