Clarify that uv run uses inexact syncing by default

docs/concepts/projects/sync.md

@@ -89,17 +89,25 @@ To opt-out of this behavior, use the `--no-editable` option.
     If the project does not define a build system, it will not be installed.
     See the [build systems](./config.md#build-systems) documentation for details.
 
-### Retaining extraneous packages
+### Handling of extraneous packages
 
-Syncing is "exact" by default, which means it will remove any packages that are not present in the
-lockfile.
+`uv sync` performs "exact" syncing by default, which means it will remove any packages that are not
+present in the lockfile.
 
-To retain extraneous packages, use the `--inexact` option:
+To retain extraneous packages, use the `--inexact` flag:
 
 ```console
 $ uv sync --inexact
 ```
 
+In contrast, `uv run` uses "inexact" syncing by default, ensuring that all required packages are
+installed but not removing extraneous packages. To enable exact syncing with `uv run`, use the
+`--exact` flag:
+
+```console
+$ uv run --exact ...
+```
+
 ### Syncing optional dependencies
 
 uv reads optional dependencies from the `[project.optional-dependencies]` table. These are

docs/guides/projects.md

@@ -198,8 +198,14 @@ version.
 
 Prior to every `uv run` invocation, uv will verify that the lockfile is up-to-date with the
 `pyproject.toml`, and that the environment is up-to-date with the lockfile, keeping your project
-in-sync without the need for manual intervention. `uv run` guarantees that your command is run in a
-consistent, locked environment.
+in-sync without the need for manual intervention. `uv run` guarantees that your command is run in an
+environment with all required dependencies at their locked versions.
+
+!!! note
+
+    `uv run` does not remove extraneous packages (those not in the lockfile) from the environment
+    by default. See [handling of extraneous packages](../concepts/projects/sync.md#handling-of-extraneous-packages)
+    for details.
 
 For example, to use `flask`:
 

docs/js/extra.js

@@ -88,6 +88,8 @@ document$.subscribe(function () {
       "concepts/projects/run/#legacy-scripts-on-windows",
     "concepts/projects/sync/#checking-if-the-lockfile-is-up-to-date":
       "concepts/projects/sync/#checking-the-lockfile",
+    "concepts/projects/sync/#retaining-extraneous-packages":
+      "concepts/projects/sync/#handling-of-extraneous-packages",
     "concepts/authentication/#git-authentication":
       "concepts/authentication/git/",
     "concepts/authentication/#git-credential-helpers":