# mcp_distinct_values

A read tool on the Mongo-MCP MCP server.

Agent View of the PolicyLayer registry record for `mcp_distinct_values`. HTML page: https://policylayer.com/tools/441126098-mongo-mcp/mcp-distinct-values

## Facts

- Tool: `mcp_distinct_values`
- Server: Mongo-MCP (`441126098/mongo-mcp`) — https://policylayer.com/tools/441126098-mongo-mcp.md
- Homepage: https://github.com/441126098/mongo-mcp
- 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": "mcp_distinct_values",
    "arguments": {}
  }
}
```

## Why mcp_distinct_values is rated Low

The 'distinct' operation in MongoDB retrieves unique values from a field without modifying data. Despite the empty description lowering confidence slightly, the name and server context clearly indicate a read operation with no side effects. No data is created, modified, deleted, or destroyed. This is a low-severity data retrieval tool.

From the tool's own definition: "Tool name 'mcp_distinct_values' indicates a query operation that retrieves distinct values from a MongoDB collection."

## Use case

AI agents call mcp_distinct_values to retrieve information from Mongo-MCP 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 Mongo-MCP:

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

## Other tools on Mongo-MCP (29)

- `mcp_delete_document` — Destructive — https://policylayer.com/tools/441126098-mongo-mcp/mcp-delete-document.md
- `mcp_drop_collection` — Destructive — https://policylayer.com/tools/441126098-mongo-mcp/mcp-drop-collection.md
- `mcp_drop_database` — Destructive — https://policylayer.com/tools/441126098-mongo-mcp/mcp-drop-database.md
- `mcp_drop_index` — Destructive — https://policylayer.com/tools/441126098-mongo-mcp/mcp-drop-index.md
- `mcp_aggregate_documents` — Execute — https://policylayer.com/tools/441126098-mongo-mcp/mcp-aggregate-documents.md
- `mcp_reindex_collection` — Execute — https://policylayer.com/tools/441126098-mongo-mcp/mcp-reindex-collection.md
- `mcp_count_documents` — Read — https://policylayer.com/tools/441126098-mongo-mcp/mcp-count-documents.md
- `mcp_find_documents` — Read — https://policylayer.com/tools/441126098-mongo-mcp/mcp-find-documents.md
- `mcp_find_one_document` — Read — https://policylayer.com/tools/441126098-mongo-mcp/mcp-find-one-document.md
- `mcp_get_collection_stats` — Read — https://policylayer.com/tools/441126098-mongo-mcp/mcp-get-collection-stats.md
- `mcp_get_connection_details` — Read — https://policylayer.com/tools/441126098-mongo-mcp/mcp-get-connection-details.md
- `mcp_get_database_stats` — Read — https://policylayer.com/tools/441126098-mongo-mcp/mcp-get-database-stats.md
- `mcp_get_replica_set_status` — Read — https://policylayer.com/tools/441126098-mongo-mcp/mcp-get-replica-set-status.md
- `mcp_get_server_status` — Read — https://policylayer.com/tools/441126098-mongo-mcp/mcp-get-server-status.md
- `mcp_list_collections` — Read — https://policylayer.com/tools/441126098-mongo-mcp/mcp-list-collections.md
- `mcp_list_databases` — Read — https://policylayer.com/tools/441126098-mongo-mcp/mcp-list-databases.md
- `mcp_list_indexes` — Read — https://policylayer.com/tools/441126098-mongo-mcp/mcp-list-indexes.md
- `mcp_ping_database` — Read — https://policylayer.com/tools/441126098-mongo-mcp/mcp-ping-database.md
- `mcp_test_mongodb_connection` — Read — https://policylayer.com/tools/441126098-mongo-mcp/mcp-test-mongodb-connection.md
- `mcp_create_collection` — Write — https://policylayer.com/tools/441126098-mongo-mcp/mcp-create-collection.md
- `mcp_create_compound_index` — Write — https://policylayer.com/tools/441126098-mongo-mcp/mcp-create-compound-index.md
- `mcp_create_database` — Write — https://policylayer.com/tools/441126098-mongo-mcp/mcp-create-database.md
- `mcp_create_index` — Write — https://policylayer.com/tools/441126098-mongo-mcp/mcp-create-index.md
- `mcp_create_text_index` — Write — https://policylayer.com/tools/441126098-mongo-mcp/mcp-create-text-index.md
- `mcp_insert_document` — Write — https://policylayer.com/tools/441126098-mongo-mcp/mcp-insert-document.md
- `mcp_insert_many_documents` — Write — https://policylayer.com/tools/441126098-mongo-mcp/mcp-insert-many-documents.md
- `mcp_rename_collection` — Write — https://policylayer.com/tools/441126098-mongo-mcp/mcp-rename-collection.md
- `mcp_replace_document` — Write — https://policylayer.com/tools/441126098-mongo-mcp/mcp-replace-document.md
- `mcp_update_document` — Write — https://policylayer.com/tools/441126098-mongo-mcp/mcp-update-document.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=441126098-mongo-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/441126098-mongo-mcp