diff --git a/src/content/docs/commands/copy.mdx b/src/content/docs/commands/copy.mdx
index d21e022330..e8fcfe3d50 100644
--- a/src/content/docs/commands/copy.mdx
+++ b/src/content/docs/commands/copy.mdx
@@ -51,6 +51,19 @@ The `copy` command is especially handy for:
 
 - `<target-branch>`: The destination branch within the same repository.
 
+## Requirements
+
+Whatever your configuration says, Mergify adds one requirement before it copies:
+the pull request has to be free of conflict with its base branch. It does not
+have to be merged, so `copy` runs on an open pull request as well as a merged
+one. The same requirement applies to [the `copy`
+action](/workflow/actions/copy).
+
+When the pull request is in conflict, the command answers that there is nothing
+to do and stops there. Unlike [`backport`](/commands/backport), which waits for
+the pull request to be merged, `copy` does not wait for the requirement to be
+met, so resolve the conflict and run it again.
+
 <CopyLimitations />
 
 ## Example
diff --git a/src/content/docs/commands/rebase.mdx b/src/content/docs/commands/rebase.mdx
index 116a08e106..5123ecd1ba 100644
--- a/src/content/docs/commands/rebase.mdx
+++ b/src/content/docs/commands/rebase.mdx
@@ -35,6 +35,19 @@ request:
 
 <Image src={rebaseScreenshot} alt="Posting '@mergifyio rebase' in GitHub interface"/>
 
+## Requirements
+
+Whatever your configuration says, Mergify adds its own requirements before it
+rebases: the pull request has to be open, free of conflict with its base branch,
+not in a merge queue, and either behind its base branch or without a linear
+history. The same requirements apply to [the `rebase`
+action](/workflow/actions/rebase).
+
+When one of them does not hold, the command answers that there is nothing to do
+and stops there. Unlike [`queue`](/commands/queue) and
+[`backport`](/commands/backport), it does not wait for the requirements to be
+met, so run it again once the pull request has something to rebase.
+
 ## Impersonation
 
 Mergify pushes the rebased branch as a GitHub user, not as itself. Unless a
diff --git a/src/content/docs/commands/update.mdx b/src/content/docs/commands/update.mdx
index 3f4c586d7c..b0daa1f5ae 100644
--- a/src/content/docs/commands/update.mdx
+++ b/src/content/docs/commands/update.mdx
@@ -16,6 +16,19 @@ take care of it.
 @Mergifyio update
 ```
 
+## Requirements
+
+Whatever your configuration says, Mergify adds its own requirements before it
+updates: the pull request has to be open, free of conflict with its base branch,
+not in a merge queue, and behind its base branch. The same requirements apply to
+[the `update` action](/workflow/actions/update).
+
+When one of them does not hold, most often because the pull request is already
+up to date, the command answers that there is nothing to do and stops there.
+Unlike [`queue`](/commands/queue) and [`backport`](/commands/backport), it does
+not wait for the requirements to be met, so run it again once the pull request
+has something to update.
+
 ## Fork Pull Requests
 
 `update` merges the base branch into the pull request rather than rewriting its