Add argument-comment Dylint runner

AGENTS.md

@@ -11,6 +11,11 @@ In the codex-rs folder where the rust code lives:
 - Always collapse if statements per https://rust-lang.github.io/rust-clippy/master/index.html#collapsible_if
 - Always inline format! args when possible per https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args
 - Use method references over closures when possible per https://rust-lang.github.io/rust-clippy/master/index.html#redundant_closure_for_method_calls
+- Avoid bool or ambiguous `Option` parameters that force callers to write hard-to-read code such as `foo(false)` or `bar(None)`. Prefer enums, named methods, newtypes, or other idiomatic Rust API shapes when they keep the callsite self-documenting.
+- When you cannot make that API change and still need a small positional-literal callsite in Rust, follow the `argument_comment_lint` convention:
+  - Use an exact `/*param_name*/` comment before opaque literal arguments such as `None`, booleans, and numeric literals when passing them by position.
+  - Do not add these comments for string or char literals unless the comment adds real clarity; those literals are intentionally exempt from the lint.
+  - If you add one of these comments, the parameter name must exactly match the callee signature.
 - When possible, make `match` statements exhaustive and avoid wildcard arms.
 - When writing tests, prefer comparing the equality of entire objects over fields one by one.
 - When making a change that adds or changes an API, ensure that the documentation in the `docs/` folder is up to date if applicable.

justfile

@@ -86,6 +86,11 @@ write-app-server-schema *args:
 write-hooks-schema:
     cargo run --manifest-path ./codex-rs/Cargo.toml -p codex-hooks --bin write_hooks_schema_fixtures
 
+# Run the argument-comment Dylint checks across codex-rs.
+[no-cd]
+argument-comment-lint *args:
+    ./tools/argument-comment-lint/run.sh "$@"
+
 # Tail logs from the state SQLite database
 log *args:
     if [ "${1:-}" = "--" ]; then shift; fi; cargo run -p codex-state --bin logs_client -- "$@"

tools/argument-comment-lint/.cargo/config.toml

@@ -0,0 +1,6 @@
+[target.'cfg(all())']
+rustflags = ["-C", "linker=dylint-link"]
+
+# For Rust versions 1.74.0 and onward, the following alternative can be used
+# (see https://github.com/rust-lang/cargo/pull/12535):
+# linker = "dylint-link"

tools/argument-comment-lint/.gitignore

@@ -0,0 +1 @@
+/target