MongoDB MCP Server

Instructions

Implementation Reference

• src/index.ts:1191-1214 (handler)

  Handler for get_collection_stats tool: extracts database and collection from arguments, connects to the database, runs db.command({ collStats: collection }) to get statistics, and returns them as JSON text content.

  case 'get_collection_stats': {
    const { database, collection } = request.params.arguments as {
      database?: string;
      collection: string;
    };
    const dbName = database || this.defaultDatabase;
    if (!dbName) {
      throw new McpError(
        ErrorCode.InvalidRequest,
        'Database name is required when no default database is configured'
      );
    }
  
    const db = client.db(dbName);
    const stats = await db.command({ collStats: collection });
    return {
      content: [
        {
          type: 'text',
          text: JSON.stringify(stats, null, 2),
        },
      ],
    };
  }

• src/index.ts:550-574 (registration)

  Registration of get_collection_stats tool in the ListTools response, including name, description, and input schema definition.

          {
            name: 'get_collection_stats',
            description: `Get detailed statistics about a collection.
  
  Returns information about:
  - Document count and size
  - Storage metrics
  - Index sizes and usage
  - Average document size
  - Padding factor`,
            inputSchema: {
              type: 'object',
              properties: {
                database: {
                  type: 'string',
                  description: 'Database name (optional if default database is configured)',
                },
                collection: {
                  type: 'string',
                  description: 'Collection name',
                },
              },
              required: ['collection'],
            },
          },

• src/index.ts:560-573 (schema)

  Input schema for get_collection_stats tool defining parameters database (optional string) and collection (required string).

  inputSchema: {
    type: 'object',
    properties: {
      database: {
        type: 'string',
        description: 'Database name (optional if default database is configured)',
      },
      collection: {
        type: 'string',
        description: 'Collection name',
      },
    },
    required: ['collection'],
  },