Please find below for mongo index stat for collection, please verify and let me know if collection is fine/tuned.

db.yyy.stats()
{
"ns" : "xxx.yyy",
"size" : 426697650,
"count" : 161519,
"avgObjSize" : 2641,
"storageSize" : 256544768,
"capped" : false,
"wiredTiger" : {
"metadata" : {
"formatVersion" : 1
},
"creationString" : "access_pattern_hint=none,allocation_size=4KB,app_metadata=(formatVersion=1),block_allocation=best,block_compressor=snappy,cache_resident=false,checksum=on,colgroups=,collator=,columns=,dictionary=0,encryption=(keyid=,name=),exclusive=false,extractor=,format=btree,huffman_key=,huffman_value=,ignore_in_memory_cache_size=false,immutable=false,internal_item_max=0,internal_key_max=0,internal_key_truncate=true,internal_page_max=4KB,key_format=q,key_gap=10,leaf_item_max=0,leaf_key_max=0,leaf_page_max=32KB,leaf_value_max=64MB,log=(enabled=true),lsm=(auto_throttle=true,bloom=true,bloom_bit_count=16,bloom_config=,bloom_hash_count=8,bloom_oldest=false,chunk_count_limit=0,chunk_max=5GB,chunk_size=10MB,merge_max=15,merge_min=0),memory_page_max=10m,os_cache_dirty_max=0,os_cache_max=0,prefix_compression=false,prefix_compression_min=4,source=,split_deepen_min_child=0,split_deepen_per_child=0,split_pct=90,type=file,value_format=u",
"type" : "file",
"uri" : "statistics:table:collection-24-3539838882717415194",
"LSM" : {
"bloom filter false positives" : 0,
"bloom filter hits" : 0,
"bloom filter misses" : 0,
"bloom filter pages evicted from cache" : 0,
"bloom filter pages read into cache" : 0,
"bloom filters in the LSM tree" : 0,
"chunks in the LSM tree" : 0,
"highest merge generation in the LSM tree" : 0,
"queries that could have benefited from a Bloom filter that did not exist" : 0,
"sleep for LSM checkpoint throttle" : 0,
"sleep for LSM merge throttle" : 0,
"total size of bloom filters" : 0
},
"block-manager" : {
"allocations requiring file extension" : 7124,
"blocks allocated" : 200493,
"blocks freed" : 126482,
"checkpoint size" : 195432448,
"file allocation unit size" : 4096,
"file bytes available for reuse" : 61054976,
"file magic number" : 120897,
"file major version number" : 1,
"file size in bytes" : 256544768,
"minor version number" : 0
},
"btree" : {
"btree checkpoint generation" : 61504,
"column-store fixed-size leaf pages" : 0,
"column-store internal pages" : 0,
"column-store variable-size RLE encoded values" : 0,
"column-store variable-size deleted values" : 0,
"column-store variable-size leaf pages" : 0,
"fixed-record size" : 0,
"maximum internal page key size" : 368,
"maximum internal page size" : 4096,
"maximum leaf page key size" : 2867,
"maximum leaf page size" : 32768,
"maximum leaf page value size" : 67108864,
"maximum tree depth" : 4,
"number of key/value pairs" : 0,
"overflow pages" : 0,
"pages rewritten by compaction" : 0,
"row-store internal pages" : 0,
"row-store leaf pages" : 0
},
"cache" : {
"bytes currently in the cache" : 78447565,
"bytes read into cache" : NumberLong("92974731983051"),
"bytes written from cache" : 2039030318,
"checkpoint blocked page eviction" : 0,
"data source pages selected for eviction unable to be evicted" : 231467,
"hazard pointer blocked page eviction" : 226227,
"in-memory page passed criteria to be split" : 0,
"in-memory page splits" : 0,
"internal pages evicted" : 1062,
"internal pages split during eviction" : 0,
"leaf pages split during eviction" : 3596,
"modified pages evicted" : 77999,
"overflow pages read into cache" : 0,
"overflow values cached in memory" : 0,
"page split during eviction deepened the tree" : 0,
"page written requiring lookaside records" : 0,
"pages read into cache" : 4588086468,
"pages read into cache requiring lookaside entries" : 0,
"pages requested from the cache" : 22973864799,
"pages written from cache" : 153597,
"pages written requiring in-memory restoration" : 5,
"tracked dirty bytes in the cache" : 0,
"unmodified pages evicted" : 4588098368
},
"cache_walk" : {
"Average difference between current eviction generation when the page was last considered" : 0,
"Average on-disk page image size seen" : 0,
"Clean pages currently in cache" : 0,
"Current eviction generation" : 0,
"Dirty pages currently in cache" : 0,
"Entries in the root page" : 0,
"Internal pages currently in cache" : 0,
"Leaf pages currently in cache" : 0,
"Maximum difference between current eviction generation when the page was last considered" : 0,
"Maximum page size seen" : 0,
"Minimum on-disk page image size seen" : 0,
"On-disk page image sizes smaller than a single allocation unit" : 0,
"Pages created in memory and never written" : 0,
"Pages currently queued for eviction" : 0,
"Pages that could not be queued for eviction" : 0,
"Refs skipped during cache traversal" : 0,
"Size of the root page" : 0,
"Total number of pages currently in cache" : 0
},
"compression" : {
"compressed pages read" : 4588080168,
"compressed pages written" : 89824,
"page written failed to compress" : 0,
"page written was too small to compress" : 63773,
"raw compression call failed, additional data available" : 0,
"raw compression call failed, no additional data available" : 0,
"raw compression call succeeded" : 0
},
"cursor" : {
"bulk-loaded cursor-insert calls" : 0,
"create calls" : 4790,
"cursor-insert key and value bytes inserted" : 443384741,
"cursor-remove key bytes removed" : 0,
"cursor-update value bytes updated" : 0,
"insert calls" : 180062,
"next calls" : 65110076080,
"prev calls" : 1,
"remove calls" : 0,
"reset calls" : 710241690,
"restarted searches" : 3,
"search calls" : 24702818336,
"search near calls" : 512716148,
"truncate calls" : 0,
"update calls" : 0
},
"reconciliation" : {
"dictionary matches" : 0,
"fast-path pages deleted" : 0,
"internal page key bytes discarded using suffix compression" : 86665,
"internal page multi-block writes" : 19633,
"internal-page overflow keys" : 0,
"leaf page key bytes discarded using prefix compression" : 0,
"leaf page multi-block writes" : 5619,
"leaf-page overflow keys" : 0,
"maximum blocks required for a page" : 2,
"overflow values written" : 0,
"page checksum matches" : 47388,
"page reconciliation calls" : 145616,
"page reconciliation calls for eviction" : 17012,
"pages deleted" : 0
},
"session" : {
"object compaction" : 0,
"open cursor count" : 637
},
"transaction" : {
"update conflicts" : 216
}
},
"nindexes" : 9,
"totalIndexSize" : 19562496,
"indexSizes" : {
"id" : 2363392,
"requestId_vertical" : 2871296,
"policyRisk.registrationNo_1" : 4165632,
"policyRisk.engineNo_1" : 2105344,
"policyRisk.chassisNo_1" : 2220032,
"proposer.fName_1" : 1994752,
"proposer.lName_1" : 1409024,
"misOwnerId_1_recordStatus_1_recordAssignedDate_1" : 1572864,
"recordStatus_1_misOwnerId_1" : 860160
},
"ok" : 1
}