[ty] Correct project option documentation

crates/ty/docs/cli.md

diff --git a/crates/ty/docs/cli.md b/crates/ty/docs/cli.md
index c830666..52394af 100644
--- a/crates/ty/docs/cli.md
+++ b/crates/ty/docs/cli.md
@@ -77,8 +77,8 @@
 <li><code>gitlab</code>:  Print diagnostics in the JSON format expected by GitLab Code Quality reports</li>
 <li><code>github</code>:  Print diagnostics in the format used by GitHub Actions workflow error annotations</li>
 <li><code>junit</code>:  Print diagnostics as a JUnit-style XML report</li>
-</ul></dd><dt id="ty-check--project"><a href="#ty-check--project"><code>--project</code></a> <i>project</i></dt><dd><p>Run the command within the given project directory.</p>
-<p>All <code>pyproject.toml</code> files will be discovered by walking up the directory tree from the given project directory, as will the project's virtual environment (<code>.venv</code>) unless the <code>venv-path</code> option is set.</p>
+</ul></dd><dt id="ty-check--project"><a href="#ty-check--project"><code>--project</code></a> <i>project</i></dt><dd><p>Discover the project from the given directory.</p>
+<p>ty searches for configuration files by walking up the directory tree from the given directory. The discovered project root is also used to find the project's virtual environment (<code>.venv</code>) and to determine which files to check when no paths are provided.</p>
 <p>Other command-line arguments (such as relative paths) will be resolved relative to the current working directory.</p>
 </dd><dt id="ty-check--python"><a href="#ty-check--python"><code>--python</code></a>, <code>--venv</code> <i>path</i></dt><dd><p>Path to your project's Python environment or interpreter.</p>
 <p>ty uses your Python environment to resolve third-party imports in your code.</p>

crates/ty/src/args.rs

diff --git a/crates/ty/src/args.rs b/crates/ty/src/args.rs
index 56972b3..9893e88 100644
--- a/crates/ty/src/args.rs
+++ b/crates/ty/src/args.rs
@@ -77,10 +77,11 @@
     #[arg(long, conflicts_with("fix"))]
     pub(crate) add_ignore: bool,
 
-    /// Run the command within the given project directory.
+    /// Discover the project from the given directory.
     ///
-    /// All `pyproject.toml` files will be discovered by walking up the directory tree from the given project directory,
-    /// as will the project's virtual environment (`.venv`) unless the `venv-path` option is set.
+    /// ty searches for configuration files by walking up the directory tree from the given directory.
+    /// The discovered project root is also used to find the project's virtual environment (`.venv`)
+    /// and to determine which files to check when no paths are provided.
     ///
     /// Other command-line arguments (such as relative paths) will be resolved relative to the current working directory.
     #[arg(long, value_name = "PROJECT")]