# mcp_create_index

A write tool on the Mongo-MCP MCP server.

Agent View of the PolicyLayer registry record for `mcp_create_index`. HTML page: https://policylayer.com/tools/441126098-mongo-mcp/mcp-create-index

## Facts

- Tool: `mcp_create_index`
- Server: Mongo-MCP (`441126098/mongo-mcp`) — https://policylayer.com/tools/441126098-mongo-mcp.md
- Homepage: https://github.com/441126098/mongo-mcp
- Risk category: Write (Medium risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Rate-limited

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

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

## Why mcp_create_index is rated Medium

Creating an index is a reversible structural modification to a MongoDB database—it changes how data is organized and indexed but does not alter or delete data itself. This qualifies as Write rather than Execute (no code execution) or Destructive (indexes can be dropped). Severity is medium because poorly chosen indexes can degrade performance and consume resources, but the impact is not catastrophic. Confidence is 0.

From the tool's own definition: "Tool name is 'mcp_create_index' with no description provided. Sibling tools include 'mcp_create_compound_index' and 'mcp_create_text_index', which are variants of index creation."

## Use case

AI agents use mcp_create_index to create or update resources in Mongo-MCP, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Mongo-MCP environment.

## Recommended policy (PolicyLayer)

Verdict: **Rate-limited**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Mongo-MCP:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "mcp_create_index": {
      "limits": [
        {
          "counter": "mcp_create_index_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## 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_distinct_values` — Read — https://policylayer.com/tools/441126098-mongo-mcp/mcp-distinct-values.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_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