diff --git a/coins/bitcoin/src/crypto.rs b/coins/bitcoin/src/crypto.rs
index bcb73936..741a0289 100644
--- a/coins/bitcoin/src/crypto.rs
+++ b/coins/bitcoin/src/crypto.rs
@@ -37,8 +37,9 @@ pub fn x_only(key: &ProjectivePoint) -> XOnlyPublicKey {
   XOnlyPublicKey::from_slice(&x(key)).expect("x_only was passed a point which was infinity or odd")
 }
 
-/// Make a point even by adding the generator until it is even. Returns the even point and the
-/// amount of additions required.
+/// Make a point even by adding the generator until it is even.
+///
+/// Returns the even point and the amount of additions required.
 pub fn make_even(mut key: ProjectivePoint) -> (ProjectivePoint, u64) {
   let mut c = 0;
   while key.to_encoded_point(true).tag() == Tag::CompressedOddY {
@@ -51,6 +52,8 @@ pub fn make_even(mut key: ProjectivePoint) -> (ProjectivePoint, u64) {
 /// A BIP-340 compatible HRAm for use with the modular-frost Schnorr Algorithm.
 ///
 /// If passed an odd nonce, it will have the generator added until it is even.
+///
+/// If the key is odd, this will panic.
 #[derive(Clone, Copy, Debug)]
 pub struct Hram;
 
diff --git a/coins/bitcoin/src/wallet/mod.rs b/coins/bitcoin/src/wallet/mod.rs
index ea91d2ae..d3575df2 100644
--- a/coins/bitcoin/src/wallet/mod.rs
+++ b/coins/bitcoin/src/wallet/mod.rs
@@ -24,12 +24,17 @@ mod send;
 pub use send::*;
 
 /// Tweak keys to ensure they're usable with Bitcoin.
+///
+/// Taproot keys, which these keys are used as, must be even. This offsets the keys until they're
+/// even.
 pub fn tweak_keys(keys: &ThresholdKeys<Secp256k1>) -> ThresholdKeys<Secp256k1> {
   let (_, offset) = make_even(keys.group_key());
   keys.offset(Scalar::from(offset))
 }
 
 /// Return the Taproot address for a public key.
+///
+/// If the key is odd, this will return None.
 pub fn address(network: Network, key: ProjectivePoint) -> Option<Address> {
   if key.to_encoded_point(true).tag() != Tag::CompressedEvenY {
     return None;
diff --git a/coins/bitcoin/src/wallet/send.rs b/coins/bitcoin/src/wallet/send.rs
index 7e245407..3d18c47c 100644
--- a/coins/bitcoin/src/wallet/send.rs
+++ b/coins/bitcoin/src/wallet/send.rs
@@ -245,7 +245,7 @@ impl SignableTransaction {
 /// A FROST signing machine to produce a Bitcoin transaction.
 ///
 /// This does not support caching its preprocess. When sign is called, the message must be empty.
-/// This will panic if it isn't.
+/// This will panic if either `cache` is called or the message isn't empty.
 pub struct TransactionMachine {
   tx: SignableTransaction,
   sigs: Vec<AlgorithmMachine<Secp256k1, Schnorr<RecommendedTranscript>>>,