diff --git a/object/service.proto b/object/service.proto
index 020e1d5..4ce47ed 100644
--- a/object/service.proto
+++ b/object/service.proto
@@ -9,93 +9,98 @@ import "object/types.proto";
 import "refs/types.proto";
 import "session/types.proto";
 
-// Object service provides API for manipulating with the object.
+// `ObjectService` provides API for manipulating objects. Object operations do
+// not interact with sidechain and are only served by nodes in p2p style.
 service ObjectService {
-  // Get the object from container. Response uses gRPC stream. First response
-  // message carry object of requested address. Chunk messages are parts of
-  // the object's payload if it is needed. All messages except first carry
-  // chunks. Requested object can be restored by concatenation of object
-  // message payload and all chunks keeping receiving order.
+  // Receive full object structure, including Headers and payload. Response uses
+  // gRPC stream. First response message carries object with requested address.
+  // Chunk messages are parts of the object's payload if it is needed. All
+  // messages, except the first one, carry payload chunks. Requested object can
+  // be restored by concatenation of object message payload and all chunks
+  // keeping receiving order.
   rpc Get(GetRequest) returns (stream GetResponse);
 
   // Put the object into container. Request uses gRPC stream. First message
-  // SHOULD BE type of PutHeader. Container id and Owner id of object SHOULD
-  // BE set. Session token SHOULD BE obtained before put operation (see
-  // session package). Chunk messages considered by server as part of object
-  // payload. All messages except first SHOULD BE chunks. Chunk messages
-  // SHOULD BE sent in direct order of fragmentation.
+  // SHOULD be of PutHeader type. `ContainerID` and `OwnerID` of an object
+  // SHOULD be set. Session token SHOULD be obtained before `PUT` operation (see
+  // session package). Chunk messages are considered by server as a part of an
+  // object payload. All messages, except first one, SHOULD be payload chunks.
+  // Chunk messages SHOULD be sent in direct order of fragmentation.
   rpc Put(stream PutRequest) returns (PutResponse);
 
-  // Delete the object from a container
+  // Delete the object from a container. There is no immediate removal
+  // guarantee. Object will be marked for removal and deleted eventually.
   rpc Delete(DeleteRequest) returns (DeleteResponse);
 
-  // Head returns the object without data payload. Object in the
-  // response has system header only. If full headers flag is set, extended
-  // headers are also present.
+  // Returns the object Headers without data payload. By default full header is
+  // returned. If `main_only` request field is set, the short header with only
+  // the very minimal information would be returned instead.
   rpc Head(HeadRequest) returns (HeadResponse);
 
-  // Search objects in container. Version of query language format SHOULD BE
-  // set to 1. Search query represented in serialized format (see query
-  // package).
+  // Search objects in container. Search query allows to match by Object
+  // Header's filed values. Please see the corresponding NeoFS Technical
+  // Specification section for more details.
   rpc Search(SearchRequest) returns (stream SearchResponse);
 
-  // GetRange of data payload. Range is a pair (offset, length).
-  // Requested range can be restored by concatenation of all chunks
-  // keeping receiving order.
+  // Get byte range of data payload. Range is set as an (offset, length) tuple.
+  // Like in `Get` method, the response uses gRPC stream. Requested range can be
+  // restored by concatenation of all received payload chunks keeping receiving
+  // order.
   rpc GetRange(GetRangeRequest) returns (stream GetRangeResponse);
 
-  // GetRangeHash returns homomorphic hash of object payload range after XOR
-  // operation. Ranges are set of pairs (offset, length). Hashes order in
-  // response corresponds to ranges order in request. Homomorphic hash is
-  // calculated for XORed data.
+  // Returns homomorphic or regular hash of object's payload range after
+  // applying XOR operation with the provided `salt`. Ranges are set of (offset,
+  // length) tuples. Hashes order in response corresponds to ranges order in
+  // request. Note that hash is calculated for XORed data.
   rpc GetRangeHash(GetRangeHashRequest) returns (GetRangeHashResponse);
 }
 
-// Get object request
+// GET object request
 message GetRequest {
-  // Request body
+  // GET Object request body
   message Body {
-    // Address of the requested object.
+    // Address of the requested object
     neo.fs.v2.refs.Address address = 1;
 
-    // Carries the raw option flag of the request.
-    // Raw request is sent to receive only the objects
-    // that are physically stored on the server.
+    // If `raw` flag is set, request will work only with objects that are
+    // physically stored on the peer node
     bool raw = 2;
   }
   // Body of get object request message.
   Body body = 1;
 
-  // Carries request meta information. Header data is used only to regulate message
-  // transport and does not affect request execution.
+  // Carries request meta information. Header data is used only to regulate
+  // message transport and does not affect request execution.
   neo.fs.v2.session.RequestMetaHeader meta_header = 2;
 
-  // Carries request verification information. This header is used to authenticate
-  // the nodes of the message route and check the correctness of transmission.
+  // Carries request verification information. This header is used to
+  // authenticate the nodes of the message route and check the correctness of
+  // transmission.
   neo.fs.v2.session.RequestVerificationHeader verify_header = 3;
 }
 
-// get object response
+// GET object response
 message GetResponse {
-  // Response body
+  // GET Object Response body
   message Body {
-    // Initialization parameters of the object got from NeoFS.
+    // Initial part of the `Object` structure stream. Technically it's a
+    // set of all `Object` structure's fields except `payload`.
     message Init {
-      // Object ID
+      // Object's unique identifier.
       neo.fs.v2.refs.ObjectID object_id = 1;
 
-      // Object signature
+      // Signed `ObjectID`
       neo.fs.v2.refs.Signature signature = 2;
 
-      // Object header.
+      // Object metadata headers
       Header header = 3;
     }
-    // Carries the single message of the response stream.
+    // Single message in the response stream.
     oneof object_part {
-      // Initialization parameters of the object stream.
+      // Initial part of the object stream
       Init init = 1;
 
-      // Part of the object payload.
+      // Chunked object payload
       bytes chunk = 2;
     }
   }
@@ -107,58 +112,58 @@ message GetResponse {
   neo.fs.v2.session.ResponseMetaHeader meta_header = 2;
 
   // Carries response verification information. This header is used to
-  // authenticate the nodes of the message route and check the correctness
-  // of transmission.
+  // authenticate the nodes of the message route and check the correctness of
+  // transmission.
   neo.fs.v2.session.ResponseVerificationHeader verify_header = 3;
 }
 
-// Put object request
+// PUT object request
 message PutRequest {
-  // Request body
+  // PUT request body
   message Body {
-    // Groups initialization parameters of object placement in NeoFS.
+    // Newly created object structure parameters. If some optional parameters
+    // are not set, they will be calculated by a peer node.
     message Init {
-      // Object ID, where available
+      // ObjectID if available.
       neo.fs.v2.refs.ObjectID object_id = 1;
 
-      // Object signature, were available
+      // Object signature if available
       neo.fs.v2.refs.Signature signature = 2;
 
-      // Header of the object to save in the system.
+      // Object's Header
       Header header = 3;
 
-      // Number of the object copies to store within the RPC call.
-      // Default zero value is processed according to the
-      // container placement rules.
+      // Number of the object copies to store within the RPC call. By default
+      // object is processed according to the container's placement policy.
       uint32 copies_number = 4;
     }
-    // Carries the single part of the query stream.
+    // Single message in the request stream.
     oneof object_part {
-      // Carries the initialization parameters of the object stream.
+      // Initial part of the object stream
       Init init = 1;
 
-      // Carries part of the object payload.
+      // Chunked object payload
       bytes chunk = 2;
     }
   }
   // Body of put object request message.
   Body body = 1;
 
-  // Carries request meta information. Header data is used only to regulate message
-  // transport and does not affect request execution.
+  // Carries request meta information. Header data is used only to regulate
+  // message transport and does not affect request execution.
   neo.fs.v2.session.RequestMetaHeader meta_header = 2;
 
-  // Carries request verification information. This header is used to authenticate
-  // the nodes of the message route and check the correctness of transmission.
+  // Carries request verification information. This header is used to
+  // authenticate the nodes of the message route and check the correctness of
+  // transmission.
   neo.fs.v2.session.RequestVerificationHeader verify_header = 3;
 }
 
-// Put object response
+// PUT Object response
 message PutResponse {
-  // Response body
+  // PUT Object response body
   message Body {
-    // Carries identifier of the saved object.
-    // It is used to access an object in the container.
+    // Identifier of the saved object
     neo.fs.v2.refs.ObjectID object_id = 1;
   }
   // Body of put object response message.
@@ -169,34 +174,35 @@ message PutResponse {
   neo.fs.v2.session.ResponseMetaHeader meta_header = 2;
 
   // Carries response verification information. This header is used to
-  // authenticate the nodes of the message route and check the correctness
-  // of transmission.
+  // authenticate the nodes of the message route and check the correctness of
+  // transmission.
   neo.fs.v2.session.ResponseVerificationHeader verify_header = 3;
 }
 
-// Object Delete request
+// Object DELETE request
 message DeleteRequest {
-  // Request body
+  // Object DELETE request body
   message Body {
-    // Carries the address of the object to be deleted.
+    // Address of the object to be deleted
     neo.fs.v2.refs.Address address = 1;
  }
   // Body of delete object request message.
   Body body = 1;
 
-  // Carries request meta information. Header data is used only to regulate message
-  // transport and does not affect request execution.
+  // Carries request meta information. Header data is used only to regulate
+  // message transport and does not affect request execution.
   neo.fs.v2.session.RequestMetaHeader meta_header = 2;
 
-  // Carries request verification information. This header is used to authenticate
-  // the nodes of the message route and check the correctness of transmission.
+  // Carries request verification information. This header is used to
+  // authenticate the nodes of the message route and check the correctness of
+  // transmission.
   neo.fs.v2.session.RequestVerificationHeader verify_header = 3;
 }
 
-// DeleteResponse is empty because we cannot guarantee permanent object removal
-// in distributed system.
+// DeleteResponse body is empty because we cannot guarantee permanent object
+// removal in distributed system.
 message DeleteResponse {
-  // Response body
+  // Object DELETE Response has an empty body.
   message Body { }
 
   // Body of delete object response message.
@@ -207,57 +213,60 @@ message DeleteResponse {
   neo.fs.v2.session.ResponseMetaHeader meta_header = 2;
 
   // Carries response verification information. This header is used to
-  // authenticate the nodes of the message route and check the correctness
-  // of transmission.
+  // authenticate the nodes of the message route and check the correctness of
+  // transmission.
   neo.fs.v2.session.ResponseVerificationHeader verify_header = 3;
 }
 
-// Object head request
+// Object HEAD request
 message HeadRequest {
-  // Request body
+  // Object HEAD request body
   message Body {
-    // Address of the object with the requested header.
+    // Address of the object with the requested Header
     neo.fs.v2.refs.Address address = 1;
 
     // Return only minimal header subset
     bool main_only = 2;
 
-    // Carries the raw option flag of the request.
-    // Raw request is sent to receive only the headers of the objects
-    // that are physically stored on the server.
+    // If `raw` flag is set, request will work only with objects that are
+    // physically stored on the peer node
     bool raw = 3;
   }
   // Body of head object request message.
   Body body = 1;
 
-  // Carries request meta information. Header data is used only to regulate message
-  // transport and does not affect request execution.
+  // Carries request meta information. Header data is used only to regulate
+  // message transport and does not affect request execution.
   neo.fs.v2.session.RequestMetaHeader meta_header = 2;
 
-  // Carries request verification information. This header is used to authenticate
-  // the nodes of the message route and check the correctness of transmission.
+  // Carries request verification information. This header is used to
+  // authenticate the nodes of the message route and check the correctness of
+  // transmission.
   neo.fs.v2.session.RequestVerificationHeader verify_header = 3;
 }
 
-// Tuple of full object header and signature of object ID.
+// Tuple of full object header and signature of `ObjectID`. \
+// Signed `ObjectID` is present to verify full header's authenticity through the
+// following steps:
+//
+// 1. Calculate `SHA-256` of marshalled `Header` structure
+// 2. Check if the resulting hash matched `ObjectID`
+// 3. Check if `ObjectID` signature in `signature` field is correct
 message HeaderWithSignature {
   // Full object header
   Header header = 1;
 
-  // Signed object_id to verify full header's authenticity through following steps:
-  // 1. Calculate SHA-256 of marshalled Headers structure.
-  // 2. Check if the resulting hash matched ObjectID
-  // 3. Check if ObjectID's signature in signature field is correct.
+  // Signed `ObjectID` to verify full header's authenticity
   neo.fs.v2.refs.Signature signature = 2;
 }
 
-// Head response
+// Object HEAD response
 message HeadResponse {
-  // Response body
+  // Object HEAD response body
   message Body {
-    // Carries the requested object header or it's part
+    // Requested object header or it's part.
     oneof head{
-      // Full object header with object ID signature
+      // Full object's `Header` with `ObjectID` signature
       HeaderWithSignature header = 1;
 
       // Short object header
@@ -272,16 +281,16 @@ message HeadResponse {
   neo.fs.v2.session.ResponseMetaHeader meta_header = 2;
 
   // Carries response verification information. This header is used to
-  // authenticate the nodes of the message route and check the correctness
-  // of transmission.
+  // authenticate the nodes of the message route and check the correctness of
+  // transmission.
   neo.fs.v2.session.ResponseVerificationHeader verify_header = 3;
 }
 
-// Search objects request
+// Object Search request
 message SearchRequest {
-  // Request body
+  // Object Search request body
   message Body {
-    // Carries search container identifier.
+    // Container identifier were to search
     neo.fs.v2.refs.ContainerID container_id = 1;
 
     // Version of the Query Language used
@@ -303,20 +312,21 @@ message SearchRequest {
   // Body of search object request message.
   Body body = 1;
 
-  // Carries request meta information. Header data is used only to regulate message
-  // transport and does not affect request execution.
+  // Carries request meta information. Header data is used only to regulate
+  // message transport and does not affect request execution.
   neo.fs.v2.session.RequestMetaHeader meta_header = 2;
 
-  // Carries request verification information. This header is used to authenticate
-  // the nodes of the message route and check the correctness of transmission.
+  // Carries request verification information. This header is used to
+  // authenticate the nodes of the message route and check the correctness of
+  // transmission.
   neo.fs.v2.session.RequestVerificationHeader verify_header = 3;
 }
 
 // Search response
 message SearchResponse {
-  // Response body
+  // Object Search response body
   message Body {
-    // Carries list of object identifiers that match the search query
+    // List of `ObjectID`s that match the search query
     repeated neo.fs.v2.refs.ObjectID id_list = 1;
   }
   // Body of search object response message.
@@ -327,48 +337,52 @@ message SearchResponse {
   neo.fs.v2.session.ResponseMetaHeader meta_header = 2;
 
   // Carries response verification information. This header is used to
-  // authenticate the nodes of the message route and check the correctness
-  // of transmission.
+  // authenticate the nodes of the message route and check the correctness of
+  // transmission.
   neo.fs.v2.session.ResponseVerificationHeader verify_header = 3;
 }
 
-// Range groups the parameters of object payload range.
+// Object payload range.Ranges of zero length SHOULD be considered as invalid.
 message Range {
-  // Carries the offset of the range from the object payload start.
+  // Offset of the range from the object payload start
   uint64 offset = 1;
 
-  // Carries the length of the object payload range.
+  // Length in bytes of the object payload range
   uint64 length = 2;
 }
 
-// Request to get part of object's payload
+// Request part of object's payload
 message GetRangeRequest {
-  // Request Body
+  // Byte range of object's payload request body
   message Body {
-    // Address carries address of the object that contains the requested payload range.
+    // Address of the object containing the requested payload range
     neo.fs.v2.refs.Address address = 1;
 
-    // Range carries the parameters of the requested payload range.
+    // Requested payload range
     Range range = 2;
   }
 
   // Body of get range object request message.
   Body body = 1;
 
-  // Carries request meta information. Header data is used only to regulate message
-  // transport and does not affect request execution.
+  // Carries request meta information. Header data is used only to regulate
+  // message transport and does not affect request execution.
   neo.fs.v2.session.RequestMetaHeader meta_header = 2;
 
-  // Carries request verification information. This header is used to authenticate
-  // the nodes of the message route and check the correctness of transmission.
+  // Carries request verification information. This header is used to
+  // authenticate the nodes of the message route and check the correctness of
+  // transmission.
   neo.fs.v2.session.RequestVerificationHeader verify_header = 3;
 }
 
 // Get part of object's payload
 message GetRangeResponse {
-  // Response body
+  // Get Range response body uses streams to transfer the response. Because
+  // object payload considered a byte sequence, there is no need to have some
+  // initial preamble message. The requested byte range is sent as a series
+  // chunks.
   message Body {
-    // Carries part of the object payload.
+    // Chunked object payload's range
     bytes chunk = 1;
   }
 
@@ -380,22 +394,22 @@ message GetRangeResponse {
   neo.fs.v2.session.ResponseMetaHeader meta_header = 2;
 
   // Carries response verification information. This header is used to
-  // authenticate the nodes of the message route and check the correctness
-  // of transmission.
+  // authenticate the nodes of the message route and check the correctness of
+  // transmission.
   neo.fs.v2.session.ResponseVerificationHeader verify_header = 3;
 }
 
 // Get hash of object's payload part
 message GetRangeHashRequest {
-  // Request body
+  // Get hash of object's payload part request body.
   message Body {
-    // Carries address of the object that contains the requested payload range.
+    // Address of the object that containing the requested payload range
     neo.fs.v2.refs.Address address = 1;
 
-    // Carries the list of object payload range to calculate homomorphic hash.
+    // List of object's payload ranges to calculate homomorphic hash
     repeated Range ranges = 2;
 
-    // Carries binary salt to XOR object payload ranges before hash calculation.
+    // Binary salt to XOR object's payload ranges before hash calculation
     bytes salt = 3;
 
     // Checksum algorithm type
@@ -404,23 +418,24 @@ message GetRangeHashRequest {
   // Body of get range hash object request message.
   Body body = 1;
 
-  // Carries request meta information. Header data is used only to regulate message
-  // transport and does not affect request execution.
+  // Carries request meta information. Header data is used only to regulate
+  // message transport and does not affect request execution.
   neo.fs.v2.session.RequestMetaHeader meta_header = 2;
 
-  // Carries request verification information. This header is used to authenticate
-  // the nodes of the message route and check the correctness of transmission.
+  // Carries request verification information. This header is used to
+  // authenticate the nodes of the message route and check the correctness of
+  // transmission.
   neo.fs.v2.session.RequestVerificationHeader verify_header = 3;
 }
 
 // Get hash of object's payload part
 message GetRangeHashResponse {
-  // Response body
+  // Get hash of object's payload part response body.
   message Body {
     // Checksum algorithm type
     neo.fs.v2.refs.ChecksumType type = 1;
 
-    // List of range hashes in a binary format.
+    // List of range hashes in a binary format
     repeated bytes hash_list = 2;
   }
   // Body of get range hash object response message.
@@ -431,7 +446,7 @@ message GetRangeHashResponse {
   neo.fs.v2.session.ResponseMetaHeader meta_header = 2;
 
   // Carries response verification information. This header is used to
-  // authenticate the nodes of the message route and check the correctness
-  // of transmission.
+  // authenticate the nodes of the message route and check the correctness of
+  // transmission.
   neo.fs.v2.session.ResponseVerificationHeader verify_header = 3;
 }
diff --git a/object/types.proto b/object/types.proto
index 0c44c89..b3fe8b9 100644
--- a/object/types.proto
+++ b/object/types.proto
@@ -8,7 +8,7 @@ option csharp_namespace = "NeoFS.API.v2.Object";
 import "refs/types.proto";
 import "session/types.proto";
 
-// Type of the object payload content
+// Type of the object payload content.
 enum ObjectType {
   // Just a normal object
   REGULAR = 0;
@@ -16,7 +16,7 @@ enum ObjectType {
   // Used internally to identify deleted objects
   TOMBSTONE = 1;
 
-  // Identifies that the object holds StorageGroup information
+  // StorageGroup information
   STORAGE_GROUP = 2;
 }
 
@@ -30,7 +30,8 @@ enum MatchType {
 
 // Short header fields
 message ShortHeader {
-  // Object format version.
+  // Object format version. Effectively the version of API library used to
+  // create particular object
   neo.fs.v2.refs.Version version = 1;
 
   // Epoch when the object was created
@@ -43,14 +44,14 @@ message ShortHeader {
   ObjectType object_type = 4;
 
   // Size of payload in bytes.
-  // 0xFFFFFFFFFFFFFFFF means `payload_length` is unknown
+  // `0xFFFFFFFFFFFFFFFF` means `payload_length` is unknown
   uint64 payload_length = 5;
 }
 
-// Object Headers
+// Object Header
 message Header {
-  // Object format version.
-  // Effectively the version of API library used to create particular object
+  // Object format version. Effectively the version of API library used to
+  // create particular object
   neo.fs.v2.refs.Version version = 1;
 
   // Object's container
@@ -63,20 +64,20 @@ message Header {
   uint64 creation_epoch = 4;
 
   // Size of payload in bytes.
-  // 0xFFFFFFFFFFFFFFFF means `payload_length` is unknown
+  // `0xFFFFFFFFFFFFFFFF` means `payload_length` is unknown
   uint64 payload_length = 5;
 
   // Hash of payload bytes
   neo.fs.v2.refs.Checksum payload_hash = 6;
 
-  // Special object type
+  // Type of the object payload content
   ObjectType object_type = 7;
 
   // Homomorphic hash of the object payload.
   neo.fs.v2.refs.Checksum homomorphic_hash = 8;
 
-  // Session token, if it was used during Object creation.
-  // Need it to verify integrity and authenticity out of Request scope.
+  // Session token, if it was used during Object creation. Need it to verify
+  // integrity and authenticity out of Request scope.
   neo.fs.v2.session.SessionToken session_token = 9;
 
   // `Attribute` is a user-defined Key-Value metadata pair attached to the
@@ -99,14 +100,15 @@ message Header {
   // User-defined object attributes
   repeated Attribute attributes = 10;
 
-  // Information about spawning the objects through a payload splitting.
+  // Bigger objects can be split into a chain of smaller objects. Information
+  // about inter-dependencies between spawned objects and how to re-construct
+  // the original one is in the `Split` headers. Parent and children objects
+  // must be within the same container.
   message Split {
-    // Identifier of the origin object.
-    // Parent and children objects must be within the same container.
-    // Parent object_id is known only to the minor child.
+    // Identifier of the origin object. Known only to the minor child.
     neo.fs.v2.refs.ObjectID parent = 1;
 
-    // Previous carries identifier of the left split neighbor.
+    // Identifier of the left split neighbor
     neo.fs.v2.refs.ObjectID previous = 2;
 
     // `signature` field of the parent object. Used to reconstruct parent.
@@ -115,19 +117,18 @@ message Header {
     // `header` field of the parent object. Used to reconstruct parent.
     Header parent_header = 4;
 
-    // Children carries list of identifiers of the objects generated by splitting the current.
+    // List of identifiers of the objects generated by splitting current one.
     repeated neo.fs.v2.refs.ObjectID children = 5;
   }
-  // Position of the object in the split hierarchy.
+  // Position of the object in the split hierarchy
   Split split = 11;
 }
 
-// Object structure.
+// Object structure. Object is immutable and content-addressed. It means
+// `ObjectID` will change if header or payload changes. It's calculated as a
+// hash of header field, which contains hash of object's payload.
 message Object {
   // Object's unique identifier.
-  // Object is content-addressed. It means id will change if header or payload
-  // changes. It's calculated as a hash of header field, which contains hash of
-  // object's payload
   neo.fs.v2.refs.ObjectID object_id = 1;
 
   // Signed object_id