diff --git a/eth-connector/src/fee.rs b/eth-connector/src/fee.rs
index cf24e5d..c2d9521 100644
--- a/eth-connector/src/fee.rs
+++ b/eth-connector/src/fee.rs
@@ -14,15 +14,22 @@ pub enum FeeType {
 
 #[derive(BorshDeserialize, BorshSerialize, Debug, Clone, Serialize, Deserialize, Copy)]
 pub struct Fee {
+    // Fee percentage in 6 decimal precision (10% -> 0.1 * 10e6 -> 100_000)
     pub fee_percentage: U128,
+    // The minimum fee amount for transfer
     pub lower_bound: Option<U128>,
+    // The maximum fee amount for transfer
     pub upper_bound: Option<U128>,
 }
 
 #[derive(BorshDeserialize, BorshSerialize)]
 pub struct FeeStorage {
+    // Enables a default fee for deposit transfers
     pub deposit_fee: Option<Fee>,
+    // Enables a default fee for withdrawal transfers
     pub withdraw_fee: Option<Fee>,
+    // Override the default fee for deposit transfers that target silos
     pub deposit_fee_per_silo: UnorderedMap<AccountId, Fee>,
+    // Override the default fee for withdrawal transfers initiated by silos
     pub withdraw_fee_per_silo: UnorderedMap<AccountId, Fee>,
 }