`read_file` exempted SKILL.md from every limit, and both injection paths
(`/skill` expansion and the `skill` tool) pasted the whole body. A 220 KB
skill put 55k tokens into the context on each call.
`cap_skill_body` cuts an over-cap body at the last line boundary that
fits (a char boundary when the body is one long line) and appends a note
that points at offset and limit. It runs before `apply_substitutions`, so
the arguments land after the cut. Both injection paths call it and log
the cut.
`read_file` returns a SKILL.md whole only while it fits the cap. Over the
cap it reads like any other file: offset and limit apply, and a window
that is still too large answers FileTooLarge. Without that the note would
send the model to a read that ignores its range.
`skill_file_skips_token_limit` pinned the exemption; it gives way to
`skill_file_over_cap_returns_file_too_large` and
`skill_file_over_cap_honors_offset_and_limit`, as upstream did.
Ported from upstream (grok-build tools skills/skill.rs cap_skill_body and
read_file skill_full, 1.0.33). Upstream's `max_output_bytes` read budget
in the same hunk is a feature and stays out.
Sweep every first-party crate source (1956 .rs files) to the project comment
guidelines: delete redundant restatements, decorative banners, change
narration, and end-of-line comments; keep and tighten the crucial ones
(invariants, bug rationale, SAFETY blocks, ported-source attribution).
No functional code changed. Every edit is proven comment-only against the
prior tree by a comment-stripping lexer (string/char/raw-string aware) plus a
separate doctest-fence check. Where removing a comment made rustfmt or clippy
want to re-lay-out adjacent code, the minimal triggering comment is restored so
code tokens stay byte-identical.
Gates green: cargo fmt --all --check (0 diffs), cargo check and cargo clippy
--workspace --all-targets (0 warnings).
Adds scripts/check_codegen_comment_guidelines.py — the enforcement gate for
these guidelines (flags banners, end-of-line comments, change narration, and
commented-out code).
ZacharyZhang-NY