# Code Audit Deep

> Line-level code audit skill. Surfaces concrete, actionable findings — perf hotspots, error-handling correctness bugs, durability / ordering bugs, memory-shape problems, function-level complexity, semantic coupling, concurrency-primitive scope mistakes, and unenforced or unfalsifiable invariants (gates that cannot reach the violation, assertions that cannot fail, rules that live only in a comment) — that file-level architectural analysis cannot see. Language-agnostic. **This skill owns the word "hotspots" when the user wants line-level findings inside files** — phrasings like "what are the hotspots", "where are the hotspots in X", "find hotspots in this file", "show me the hotspots", "any hotspots in commit.rs?" all trigger this skill; prefer this over `architectural-hotspots` whenever the user is pointing at code and asking what's wrong with it, rather than asking which files in the repo are structurally suspect. Also trigger on "audit this", "review this code", "audit X", "review X", "find bugs in X", "what'

- Skill: `stoica-mihai/code-audit-deep` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add stoica-mihai/code-audit-deep`
- Raw SKILL.md: https://api.skillmd.com/api/skills/stoica-mihai/code-audit-deep/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Security
- Author: Stoica-Mihai (https://skillmd.com/u/stoica-mihai)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/stoica-mihai/code-audit-deep

---


# Code Audit (Deep)

Line-level audit. Companion to `architectural-hotspots`. Hotspots ranks
files by structural shape (fan-in, fan-out, LOC, cycles); this skill
reads files and emits specific, actionable findings with line numbers
and fix sketches.

The core failure mode this skill exists to prevent: producing vague
"consider refactoring X" advice instead of `commit.rs:426 — clock
sampled per element in hot loop; hoist or seed-and-increment`. The
first is what a graph tool already said; the second is what the user
actually wanted.

## Language scope

This skill is **language-agnostic**. The smells below are concepts that
recur across stacks; the parenthetical examples are illustrative for a
few common languages but never exhaustive. When you read a file, map
each smell to the *equivalent* construct in the target language:
- "fallible call return value discarded" covers `let _ = f()` (Rust),
  bare `f()` ignoring its `error` return (Go), `try: f(); except:
  pass` (Python), unawaited `f()` returning a Promise (TS / JS), `_,
  _ = f()` patterns (Lua / Go), `f(); // ignore` everywhere.
- "owned-when-borrow-suffices" covers `Vec<String>` vs `Vec<&str>`
  (Rust), `[]string` copies vs slice aliases (Go), deep-copying lists
  (Python), `.slice()` cloning vs index access (JS), `std::string` vs
  `std::string_view` (C++).
- "lock-when-atomic-suffices" covers `Arc<Mutex<u64>>` (Rust),
  `sync.Mutex` for a counter (Go), `threading.Lock` around an int
  (Python), `Object.synchronized` for a primitive (Java).

Never report a finding using a language construct the project does not
use. Substitute the project's equivalent before writing the fix sketch.

## When to run

Use whenever the user wants *findings inside code* rather than *rankings
across files*. Triggers include:

- "audit `commit.rs`" / "review `plan.rs`"
- "find perf issues in this module"
- "what could go wrong in `apply_changes`?"
- "deep review of the parser"
- "where is this slow?"
- After running `architectural-hotspots` and the user wants the next
  level of detail on the flagged files.

Do **not** use when the user wants:
- Architectural overview / rankings → that's `architectural-hotspots`.
- Style / formatting issues → clippy / eslint / ruff / staticcheck etc.
- Security review of specific CVE classes → a dedicated security skill
  should run. Overlap is fine; this skill won't hunt for known CVEs.
- A single trivial bug fix in a known file — just fix it.

## Method

The strength of this skill comes from depth, not breadth. Better to
audit three files thoroughly than ten superficially.

0. **Find the project's record of already-rejected findings** before
   reading any code: `DECISIONS.md`, ADRs, a "rejection ledger" or
   "verified negatives" section, `*findings*.md`, dismissed-issue
   labels. Ask the user if nothing turns up and the repo looks mature.
   Re-raising something the team already considered and rejected on
   the record costs more credibility than the finding was ever worth,
   and it is the fastest way to get an audit ignored wholesale. When
   you drop a candidate for this reason, name the entry — that tells
   the user their record is being read, not that you found nothing.

1. **Pick targets.**
   - If the user named files, those are the targets.
   - If not, and a recent hotspots report exists, take the top 3-5
     files by combined signal (god + hub, god + tangle, or any file
     inside a cycle).
   - If neither, ask the user *which files* — not "should we audit?"
     but "which files do you want audited?" so the answer drives
     work.

2. **Read every function body end to end.** Headers and type
   signatures are not enough. A finding requires a line number, and a
   line number requires having read the line. Do not skip a function
   because its name sounds boring or routine — `apply_changes`,
   `commit_one`, `cleanup`, `recover`, `flush` often hold the
   subtle ordering bugs. Skim-reading is the dominant failure mode of
   this skill — defend against it actively by asking, for each
   function, "if this had a bug, where would it be?".

   **Reading *until the finding appears* is a separate failure from
   reading too little, and it feels like diligence.** You read the
   body, you found the line that confirms the bug, and you stopped —
   one statement before the guard that made it safe. Reading
   `Motion::Last => adj.upper()` and reporting an unbounded scroll is
   correct up to the very next statement,
   `adj.set_value(to.clamp(lower, ceiling))`, which disproves it. The
   fix is a habit, not more effort: after a candidate appears, keep
   reading to the end of the enclosing block and ask "what here would
   make this not a bug?" — then answer it before writing the finding.

3. **First pass: glyph sweep.** Before going deep on novel findings,
   do a fast scan at the *language-glyph level* — every smell below
   lists concrete syntactic glyphs in several languages. These glyphs
   are where the obvious bugs hide; missing them to chase one
   interesting novel finding is a regression of attention. After the
   glyph sweep produces its candidate list, *then* go deep on
   higher-order concerns (durability ordering, coupling, axis-
   specific structural issues).

4. **Audit along the eight axes** (next section). Most files only hit
   three or four. Don't reach for findings in an axis that genuinely
   doesn't apply.

5. **Emit findings in the fixed format** (later section). Categorized.
   `file:line`. One-line symptom. One-line fix sketch. No paragraphs
   of prose around each finding — the user is reading for signal.

6. **Prove what you can; label the rest.** For each finding, name the
   command that would *falsify* it, and run it. If no such command
   exists, mark the finding **traced** rather than **proved**. Both
   are publishable — a traced finding backed by an honest label is
   useful, a traced finding presented as measured is a liability.

   The trap this closes is specific and common: running a real check
   *near* the claim and letting it stand in for the claim. Reading
   `Motion::Last => adj.upper()`, measuring how the toolkit clamps
   adjustments, and reporting the finding verified — while the very
   next statement was `adj.set_value(to.clamp(lower, ceiling))` — is
   a measurement of the wrong thing, and the label "verified" is what
   makes it damaging. The question is never "did I run something?"
   but "would this command have come out differently if the finding
   were false?"

   Before hand-rolling a harness, check whether the language already
   has the tool: mutation testers, fuzzers, sanitizers, and coverage
   tools mechanize a whole class of proof, and a replica you wrote
   this afternoon is a slower substitute you also have to trust.
   Verify what the tool actually does before citing it.

7. **Pick the top 3-5 highest-leverage fixes** out of the full list
   and name them at the end. This is the deliverable the user will
   actually act on first.

## The eight axes

Each axis answers a different question. They are deliberately
orthogonal — a finding belongs in exactly one category.

### 1. Perf

*What is making this slow that shouldn't be?*

Smells:
- **Syscalls / IO inside a per-element loop.** File-system probes
  (exists / stat / metadata / readdir), opens, reads, network
  round-trips, DB queries — fine once, expensive per element.
  Glyphs: Rust `std::fs::{metadata,exists,read}` / `Path::exists`;
  Go `os.Stat` / `os.Open`; Python `os.path.exists` / `open()`;
  JS `fs.existsSync` / `fs.statSync`; C `stat()` / `open()` /
  `access()`.
- **Clock / RNG / time calls per element.** Wall-clock or
  monotonic-clock samples, RNG draws, UUID generations done per
  iteration when one sample-and-increment would do.
  Glyphs: Rust `SystemTime::now()` / `Instant::now()` / `rand::*`;
  Go `time.Now()` / `rand.Int*`; Python `time.time()` /
  `datetime.now()` / `random.*` / `uuid.uuid4()`; JS `Date.now()` /
  `performance.now()` / `Math.random()`; C `clock_gettime` /
  `gettimeofday` / `rand()`.
- **Allocation in hot loop.** Building a fresh container, formatting
  a fresh string, copying a non-trivial value each iteration when a
  reused buffer or borrowed view would do.
  Glyphs: Rust `String::new()` / `Vec::new()` / `.to_owned()` /
  `.clone()` / `format!(...)`; Go `[]T{}` literal / `make(...)` /
  `fmt.Sprintf` / `string([]byte)`; Python list/dict comprehension /
  `f"..."` / `copy.copy` / `copy.deepcopy`; JS array literal `[…]` /
  template literal in inner loop / `Object.assign({}, …)` / spread;
  C++ `std::string`/`std::vector` constructor in loop body.
- **Full re-scans where incremental would do.** Re-running a regex
  / parse / hash over the *entire* post-image to detect changes that
  could be tracked at write-time. Re-walking a tree that was just
  walked.
- **Redundant parse / compile.** Same input parsed twice. Same
  pattern compiled in two code paths. Same query / plan built per
  call instead of cached.
  Glyphs: regex `Pattern::compile` / `re.compile` / `new RegExp`
  inside a function called per request; SQL `prepare` per request;
  tree-sitter `Query::new` / parser `set_language` per call.
- **Forced materialization.** Collecting a stream into a fully
  materialised container whose only consumer is one-pass iteration.
  Glyphs: Rust `.collect::<Vec<_>>()` followed by `.iter()`; Go
  full slice from iterator then range; Python `list(...)` then
  `for x in ...`; JS `Array.from(...)` then `.forEach`.

How to look: read the body of every loop. Ask "is this O(work-per-item)
or am I doing O(work-per-file * items)?".

### 2. Correctness — error handling

*Where do errors silently disappear?*

Smells:
- **Fallible call whose return value is discarded.** Often
  intentional (best-effort cleanup) but often a hidden bug. If
  intentional, a comment explains why. If no comment, suspect.
  Glyphs: Rust `let _ = f()` / `f().ok();` / `f().unwrap_or(...)` with
  no log; Go bare `f()` ignoring `err` return / `_ = f()`; Python
  `try: f(); except: pass` / `try: f(); except Exception: pass`;
  JS unawaited Promise (`f();` where `f` returns `Promise`) /
  `.catch(() => {})`; C++ `(void)f();` / discarded `int` return;
  C bare `unlink(p);` ignoring `-1`.
- **Error converted to absent-value type, original error dropped.**
  The error type carried useful information; the caller has lost it.
  Glyphs: Rust `r.ok()` / `r.err()` then dropping the other side;
  Go `if err != nil { return nil }` / `return val, nil` swallowing
  err; Python `try: ...; except: return None`; JS
  `try { ... } catch { return undefined }`.
- **First-error-wins aggregation** where the caller needs to see
  *all* failures. Common in parallel / batch contexts — collecting
  results and returning only the first `Err` hides every other
  failure.
  Glyphs: Rust `.collect::<Result<Vec<_>, _>>()` /
  `results.into_iter().find(|r| r.is_err())` / Rayon `.try_reduce`;
  Go `errgroup.Wait()` returning first non-nil; Python
  `next(e for e in errs if e)`; JS `Promise.all` short-circuit
  vs `Promise.allSettled`.
- **Cleanup / rollback / recover function whose own failures are not
  surfaced.** A rollback that itself calls a fallible operation and
  returns `()` is hiding partial-state bugs.
  Glyphs: any `rollback` / `cleanup` / `recover` / `compensate` /
  `unwind` function whose signature returns `()` / `void` / `None`
  but whose body invokes fallible IO (`rename`, `unlink`, `flush`).
- **Early-return inside a loop where one bad element should not
  abort the batch (or vice versa — should fail fast but does not).**
  Glyphs: Rust `?` inside `for`; Go `if err != nil { return err }`
  inside `range`; Python bare `raise` inside `for`; JS `throw`
  inside `forEach`.
- **`match` / `switch` arms that absorb specific error variants
  without comment** — silently classify an error as success.
  Glyphs: Rust `Err(_) => return Ok(...)`; Go
  `case errors.Is(err, X): return nil`; Python `except SpecificError:
  pass`; JS `catch (e) { if (e.code === 'X') return; }`.
- **fsync / flush failure ignored** — only observable when the OS
  later loses data.
  Glyphs: Rust `let _ = file.sync_all()` / `let _ = file.flush()`;
  Go `_ = f.Sync()` / unchecked `Close()`; Python `os.fsync` in
  a `try/except: pass`; C bare `fsync(fd);` ignoring `-1`.
- **Byte-by-byte text manipulation losing UTF-8 / encoding info.**
  Iterating raw bytes and pushing them into a text container as if
  they were codepoints corrupts every multibyte character.
  Glyphs: Rust `out.push(b as char)`; Go `string(b)` where `b` is
  one byte of a multibyte rune; Python operating on bytes and
  decoding wrong / mixing `str` and `bytes`; JS `String.fromCharCode`
  in a UTF-8 byte loop; C `wchar_t` cast from `unsigned char`.
- **Identifier / index conflation.** Function expects positional
  index (e.g. 0-based child index), caller passes opaque identifier
  (e.g. pointer-derived node id) cast to the same numeric type. The
  types align so the compiler is silent. Glyphs: any `as u32` /
  `int(...)` / `uintptr` cast that joins two semantically different
  numbers; APIs named `…_for_index` vs `…_for_id` consumed
  interchangeably; tree-sitter `field_name_for_child` vs
  `field_name_for_named_child` mismatch is the canonical example.

### 3. Correctness — durability / ordering

*If the process dies mid-operation, what state remains?*

Smells, applicable any time the code mutates shared / persisted /
external state:
- **Effect ordered before its precondition is durable.** Deleting
  backups before fsyncing the new content's parent directory. Removing
  the old row before the new row is committed. Releasing the
  in-memory lock before the on-disk update is observable.
- **Commit before fsync.** Reporting success before the write is
  durable.
- **Cache invalidation before write.** Readers can observe the gap.
- **Lock released before the protected state is fully published.**
- **Compensating-action ordering wrong.** Rollback does steps in
  same order as forward path, leaving an inconsistent intermediate.
- **Parent-directory fsync skipped.** On POSIX, a fsynced file in
  an un-fsynced directory can vanish on crash. Easy to forget.

How to look: trace the *order of side-effects* through each function
that touches shared state. Ask "if I crash here, can a reader see
the new state without the old state, or vice versa, in a way the
contract forbids?".

### 4. Concurrency / pool placement

*Are concurrency primitives installed in the scope the caller
expects?*

Smells:
- **Worker pool / thread pool installed around the wrong scope.**
  The user-facing flag (`--threads N`, `--concurrency M`) is honored
  in one phase but ignored in another because the pool wasn't
  scoped wide enough.
- **Async runtime spawned per call** instead of shared.
- **Connection pool / channel pool created at wrong unit of work**
  (per-request when it should be per-process, per-process when it
  should be per-tenant).
- **Per-thread state read from cross-thread context** (or vice
  versa).
- **`spawn` / `Promise.all` / `errgroup` with no bound on
  parallelism** — accidentally unlimited fan-out under load.
- **Single-threaded fast-path inside otherwise-parallel pipeline**
  — a serial bottleneck masked by aggregate timing.

How to look: find every place the project defines a pool, an
executor, a runtime, a spawn site. For each one, identify the
*scope* it covers and the *scope* the caller assumed. Mismatches
are the bug.

### 5. Memory shape

*What is held in memory that doesn't need to be, or held twice?*

Smells:
- **Pre- and post- of the same data held together.** Struct holds
  full new text *and* the rendered diff of old→new. The diff already
  encodes the new text relative to old — keeping both doubles
  per-item footprint.
- **Owned-when-borrow-suffices.** A copy is taken where a view or
  reference into the original would be safe given lifetimes /
  ownership.
  Glyphs: Rust `Vec<String>` vs `Vec<&str>` / `String` field where
  `&str` suffices / `.to_owned()` on a value that outlives the
  borrow; Go full-slice copy `append([]T{}, src...)` vs slice
  alias; Python `list(other)` vs reference / `copy.copy`; JS
  `[...arr]` / `Array.from(arr)` for read-only iteration;
  C++ `std::string` vs `std::string_view`.
- **Lock-when-atomic-suffices.** A mutex protects a value that fits
  in a machine word and could be an atomic.
  Glyphs: Rust `Arc<Mutex<u64>>` / `Arc<Mutex<bool>>`; Go
  `sync.Mutex` around an `int64` counter; Java `synchronized` for
  a `long` / `boolean`; Python `threading.Lock` around an `int`.
- **Variant-size disparity.** One large variant of a discriminated
  union inflates every instance — boxing the large variant fixes.
  Glyphs: Rust `enum { Small(u8), Huge([u8; 4096]) }`; C++ `union`
  / `std::variant` with size-imbalanced alternatives; Go interface
  holding inconsistently-sized concrete types.
- **Long-lived cache with no eviction policy.**
- **Whole-input buffer where a stream would work** — tool that
  could pipeline reads holds the entire input in memory.
  Glyphs: Rust `fs::read_to_string` / `Vec::from_iter` on a stream;
  Go `io.ReadAll`; Python `f.read()` then process; JS
  `await response.text()` on a 1GB response.
- **Optional / nullable field that is always populated in
  practice** — the absent case is dead, the wrapper costs bytes
  and forces every reader to handle a case that cannot occur.
  Glyphs: Rust `Option<T>` field whose constructor always sets
  `Some(...)`; Go `*T` always non-nil; Python `Optional[T]`
  annotation but never `None`; TS `T | undefined` that's never
  undefined in practice.

### 6. Function-level complexity

*Where is one function doing too much, or too dangerously?*

Visible only by reading function bodies — graph tools miss these
because they live below the file boundary.

Smells:
- **Recursion with no depth bound** — especially on data derived
  from user input (parser, walker, AST visitor, JSON decoder).
  Stack-overflow vector. The iterative-stack version is usually
  one rewrite away.
- **Function > ~80 lines doing more than one thing.**
- **Dispatch / switch / match with > ~10 arms** — often a table or
  registry pattern is clearer and easier to extend.
- **Closure / inner function capturing many outer mutable
  variables** — usually a struct trying to be born.
- **Function with > 5 parameters** — parameter object or builder.
- **Two functions whose bodies differ only by a constant or a
  branch** — collapse to one parameterised version.

### 7. Coupling — semantic, not graph

*What couples that the import graph cannot see?*

`architectural-hotspots` sees file-to-file imports. This axis
catches the rest:
- Two modules look orthogonal but both call the same set of
  helpers from a third — they share an implicit protocol that
  wants to be made explicit.
- A "library" module that branches on a value it gets from exactly
  one caller — the abstraction has one user. Inline it or own the
  branch in the caller.
- **Dual orchestrators with overlapping responsibilities** — one
  orchestrator can usually absorb the other, or both should
  delegate to a thinner core. Hotspots flags both as "tangles"
  without naming the relationship.
- Type defined in module A, used only by module B — wrong home.
- "Generic" helper used only by one site — not generic, just
  premature.
- Two functions doing the same operation in slightly different
  ways across modules — same shape, divergent details.

### 8. Enforcement — is the invariant actually held?

*The project states a rule. Does anything make it true?*

Every other axis asks what the code does. This one asks whether the
guard on the code can fire. It is the axis that catches **a check
that passes for the wrong reason**, and it is invisible to the other
seven because nothing is wrong with the code under the guard — the
guard is wrong about its own reach.

Classify each invariant the project claims into three states. Only
one of them is safe:

- **Derived** — the check computes the invariant from the thing under
  test, so it moves when the code moves. Safe.
- **Asserted** — the check names the value or symbol literally. It
  holds today and goes stale silently the moment the code is renamed,
  inlined, or restated somewhere the pattern does not reach. Finding.
- **Absent** — the rule exists only in prose: a comment, a README, a
  docstring, a convention. Nothing enforces it. Finding.

Smells:
- **Assertion that cannot fail.** The check's inputs and its expected
  value both derive from the single artifact under test, so it is
  true by construction. Tell: a docstring promising a comparison
  ("compares X against the Y baseline") beside an assertion that
  reads only X. A sibling step in the same block that *does* carry a
  floor is strong evidence the missing one was an oversight.
- **One-sided check on a two-sided property.** Asserting the bad
  state disappears without asserting the good state survives. A fix
  that suppresses *everything* passes. Anything with a mirror,
  an inverse, or an on/off needs both exercised.
- **Gate whose selection rule cannot reach the violation.** A
  source-scanning check has several independent filters — which files
  it reads, at what granularity, which keywords it matches, what name
  shapes it accepts. A violation outside any one filter is invisible
  while the gate stays green. Audit the rule by re-running it with
  one filter widened at a time.
- **Literal where the gate matches a symbol.** A gate keyed on
  `const NAME` cannot see the same value written as a bare number,
  and a gate matching named constants cannot see a magic literal —
  including the same value restated in a second language.
- **Invariant stated only in prose.** "Callers must…", "never call
  this before…", "keep these two lists in sync" next to shared
  mutable state or a required order. See `code-smells`' *Invariant by
  Convention* entry — that skill names the design smell, this axis
  reports the specific unenforced site.
- **Documentation citing something that no longer exists.** A doc
  naming a test, gate, or symbol that was deleted. Especially where a
  gate exists to catch exactly this and its filters miss the file,
  the verb, or the qualified name shape.

How to look: list every rule the project asserts about itself — gate
scripts, CI steps, test names, "must"/"never" comments, README
guarantees. For each, find the code that makes it true. **Read the
gate's implementation, never its name** — the name describes the
intent, and the gap between intent and selection rule is the finding.

Note this axis judges the *project's own* checks, which includes any
you or a predecessor added. A check you wrote and never watched fail
belongs here.

## Output format

Use this exact template. Counts in the headings let the user scan
volume at a glance. Omit any section with zero findings — do not
pad.

```
**Perf (N)**
- `file:line` — symptom in ≤8 words. Fix: <one short phrase>.

**Correctness (N)**
- `file:line` — symptom. Fix: <one short phrase>.

**Durability/ordering (N)**
- `file:line` — symptom. Fix: <one short phrase>.

**Concurrency (N)**
- `file:line` — symptom. Fix: <one short phrase>.

**Memory (N)**
- `file:line` — symptom. Fix: <one short phrase>.

**Complexity (N)**
- `file:line` — symptom. Fix: <one short phrase>.

**Coupling (N)**
- `file_a:line + file_b:line` — symptom. Fix: <one short phrase>.

**Enforcement (N)**
- `file:line` — invariant, and which of derived/asserted/absent it is.
  Fix: <one short phrase>.

**Top targets**
3-5 highest-leverage fixes, named with file + symptom.
```

Mark any finding you could not falsify by running something with a
trailing `[traced]`. Say once, at the end, how many findings were
proved and how many traced. A reader who knows which half is which
can act on both; a reader who cannot tell has to re-check all of them.

### Examples

Good:

> **Perf (2)**
> - `commit.rs:426` — clock sampled per nonce in hot path. Fix:
>   sample once at construction, increment a counter.
> - `commit.rs:328` — FS-probe syscall per backup entry. Fix:
>   single directory listing, then filter in memory.
>
> **Durability/ordering (1)**
> - `commit.rs:301` — backup deleted before parent-dir fsync.
>   Fix: fsync parents first, then unlink backups.
>
> **Concurrency (1)**
> - `main.rs:343` — `--threads` flag scoped only around planner;
>   apply phase runs on global pool. Fix: install scoped pool
>   around the whole pipeline.

Bad (vague, no line, no fix):

> Consider refactoring `commit.rs` for performance. Some
> operations may be inefficient.

Bad (over-prosaic, paragraph form):

> Looking at `commit.rs`, around the nonce generator, I noticed
> that it samples the wall clock, which involves a syscall. This
> could be slow if called many times, although it depends on the
> use case…

The format constraint matters because the user reads dozens of
findings; signal density wins.

## Calibration

Finding counts depend far more on the codebase than on the line
count, so treat any number here as a prompt to re-examine, never as
a quota.

**Do not scale a per-file range up across files.** A rough anchor for
one unfamiliar ~500-line file with no local discipline is a handful
to a dozen findings. Four files is not four times that. On a mature
codebase — dense justifying comments, its own gates, a written record
of rejected findings — single digits *across several files* is the
honest result, and the padding pressure is the real risk. Auditing
2400 lines and reporting eight findings with a stated coverage claim
is a better deliverable than thirty with twenty-two of them reaching.

Two outcomes worth stating plainly rather than hiding:
- **A file yielding one finding, or none.** Say so. "I read all of
  `ops.rs` and found one thing" is information. Quietly padding to
  three destroys the signal in the other two.
- **A low total because the project already rejected these.** Name
  the record you read (step 0). That is coverage, not absence.

More than ~25 findings on one file almost always means the bar
dropped. Cut to the ones that survive the table below.

Every finding must survive the "would the user act on this?"
test:

| Finding | Acts on it? |
|---|---|
| `commit.rs:426 — clock per nonce, hoist` | yes |
| `commit.rs:301 — backups deleted before fsync, swap order` | yes |
| `commit.rs is long, consider splitting` | no — that's hotspots |
| `function could be more idiomatic` | no — that's clippy |
| `naming could be clearer` | no — not what this skill is for |

When in doubt, drop it.

## Anti-patterns

- **Skim-reading.** Defaulting to function signatures and headers,
  emitting findings about "what the function probably does".
  Always read bodies before claiming a finding. The most
  bug-prone functions are the ones whose names sound mundane —
  read them first, not last.
- **Reporting in the wrong language.** Writing a Rust-flavoured
  fix sketch for a Python project. Match the project's actual
  stack.
- **Findings the codebase already addresses.** A safety
  annotation, a documented "ignore error here because X", a
  comment explaining why a clone is required — not findings.
  Read the comments.
- **…but a comment explaining a *mechanism* is a hypothesis, not a
  reason to drop.** "Safe because the toolkit never reuses the
  widget", "these paths would agree only by accident", "this cannot
  overflow because the caller validates" — each is a factual claim
  about behaviour, and the axes apply to it exactly as they apply to
  code. Dropping a real finding because a comment asserted it was
  fine is the same error as reporting a false one, and it is harder
  to catch because it leaves no trace in the output. Check the
  explanation, then drop it or keep it. (Measured example: a comment
  justified a re-cut on the grounds that widget reuse was
  coincidental; a probe under the project's own headless display
  showed 196 of 197 rebinds returned the item to the same widget, so
  the stated reason was false and the finding was real.)
- **Hand-waving "consider X" verbs.** Replace with concrete
  imperatives: *hoist*, *inline*, *collapse*, *extract*, *box*,
  *bound the recursion*, *aggregate all errors*, *swap order*,
  *scope the pool*.
- **Trying to be exhaustive.** A focused list of 10 real findings
  beats a sprawling list of 25 mostly-noise. The user picks 3-5
  to act on either way.
- **Confusing axes.** Durability/ordering bugs are not perf
  bugs. Concurrency-scope mistakes are not correctness in the
  error-handling sense. Pick the axis that points to the right
  fix shape.

