diff --git a/base/libgit2/types.jl b/base/libgit2/types.jl
index 874b93f919ecd..f74a1499d1008 100644
--- a/base/libgit2/types.jl
+++ b/base/libgit2/types.jl
@@ -50,6 +50,12 @@ end
 
 An action signature (e.g. for committers, taggers, etc).
 Matches the [`git_signature`](https://libgit2.github.com/libgit2/#HEAD/type/git_signature) struct.
+
+The fields represent:
+  * `name`: The full name of the committer or author of the commit.
+  * `email`: The email at which the committer/author can be contacted.
+  * `when`: a [`TimeStruct`](@ref) indicating when the commit was
+     authored/committed into the repository.
 """
 struct SignatureStruct
     name::Ptr{UInt8}  # full name of the author
@@ -359,6 +365,20 @@ end
     LibGit2.DescribeOptions
 
 Matches the [`git_describe_options`](https://libgit2.github.com/libgit2/#HEAD/type/git_describe_options) struct.
+
+The fields represent:
+  * `version`: version of the struct in use, in case this changes later. For now, always `1`.
+  * `max_candidates_tags`: consider this many most recent tags in `refs/tags` to describe a commit.
+     Defaults to 10 (so that the 10 most recent tags would be examined to see if they describe a commit).
+  * `describe_strategy`: whether to consider all entries in `refs/tags` (equivalent to `git-describe --tags`)
+     or all entries in `refs/` (equivalent to `git-describe --all`). The default is to only show annotated tags.
+     If `Consts.DESCRIBE_TAGS` is passed, all tags, annotated or not, will be considered.
+     If `Consts.DESCRIBE_ALL` is passed, any ref in `refs/` will be considered.
+  * `pattern`: only consider tags which match `pattern`. Supports glob expansion.
+  * `only_follow_first_parent`: when finding the distance from a matching reference to the described
+     object, only consider the distance from the first parent.
+  * `show_commit_oid_as_fallback`: if no matching reference can be found which describes a commit, show the
+     commit's [`GitHash`](@ref) instead of throwing an error (the default behavior).
 """
 @kwdef struct DescribeOptions
     version::Cuint             = 1