A week ago I installed the TypeScript LSP plugin for Claude Code. The pitch sold me. The agent works the way I do in an editor, navigating with go-to-definition and find-references instead of grepping around, and catching type errors as it writes instead of at the end of a task. I watched it work in that session and forgot about it.
A week later I went back to check what it had bought me. Nine calls, all inside the session where I tested it, on August 25. Zero across the twenty-seven sessions since.
That was annoying enough to go digging.
I pulled every session transcript from ~/.claude/projects
for one repo, a large Next.js app I work in daily. 76 sessions, 8,343 tool calls, all on Opus 5, July 31 to September 1.
Across the whole period Bash took 70% of all tool calls. Over the last two weeks, 84%, while the built-in file tools fell to 7%.
(defaultMode: "auto"
the whole window, so that didn't change.)
Grep
and Glob
were called zero times in 8,343 tool calls. grep
ran 1,165 times through Bash and rg
another 116.
Here's one from my transcripts, reading a file:
sed -n 269,352p src/domains/billing/server/database/read.ts
This one ran three times in a row across different files:
perl -pi -e 's{\bvendorContracts\b}{importedContracts}g' previewVendorContractsSyncFunction.ts
perl -pi
to rename a symbol. In a repo where the LSP plugin with
find-references was installed and enabled. I stared at that one for a while, wondering if some phrasing of mine had nudged it toward the shell. No idea. There were 325 python3
and perl
rewrites doing what Edit
does natively.
When Claude actually modified a file it mostly used Edit
and Write
. The swaps happen when it reads and searches.
The permissions docs explain a big chunk of it. A fixed set of Bash commands runs with no permission prompt in every mode:
These include
ls
,cat
,head
,grep
,find
, and read-only forms of
git
. The set is not configurable.
Every shell command it reached for instead of a built-in is on that list. 22%of my 5,837 Bash calls used nothing but commands from that list, 31% counting git
. None of them ever prompted.
Two of the rules in my deny list:
"deny": ["Read(**/.env)", "Bash(rm -rf:*)"]
Here is a command from my own transcripts, August 11:
DB=$(grep -m1 '^DATABASE_URL' .env | sed 's/^DATABASE_URL=//; s/^"//; s/"$//') \
&& psql "$DB" -c 'select u.email, um."organizationId", o.name, um.role from "User" u ...'
Read(**/.env)
is denied, but that call is not a Read
. It is a grep
, on the prompt-free list, so it never asked.
The v2.1.116 changelog says Glob and Grep are deliberately removed on native macOS and Linux builds, "replaced by embedded bfs
and ugrep
available through the Bash tool — faster searches without a separate tool round-trip." On my machine, which bfs ugrep
finds neither. The tools reference still lists Grep
and Glob
. The native build ships neither them nor the replacements.
I don't know whether that is deliberate or a build regression nobody caught.
There are open issues either way.#64136 ties the missing tools to Bash storms and fabricated file paths.
#52121 describes my exact setup, and calls it "particularly problematic for systems where bash grep/find are restricted by permission policies, as there's no alternative code-search path." And #80267, labelled
reproduced
by maintainers, treats shell-based file editing as normal: diagnostics go stale "because Claude Code likes to use sed
, python
, and similar tools to edit files in place".
An undocumented env var helped a little (CLAUDE_CODE_THRIFTY_SONIC=false
, mentioned in one of those issues, documented nowhere). Read
and Edit
came back, grep
still won. So I wrote a PreToolUse
hook that denies Bash for
anything a built-in tool does better.
Blocking grep
did not make Claude reach for Grep
. It reached for git grep
, then git ls-files
, and I had to close those specifically. With those closed, it finally uses the right tools. It costs a few calls at the start of every session while the model works out what's blocked.
A hook that blocks grep
and find
leaves no search path at all. So the current setup allows rg
, fd
, ls
, grep
and find
through and keeps denying the rest.
The hook and the scripts are at Dionysos5/claude-code-tool-mix.
Nothing in my settings changed. I only found out because a plugin got zero calls.
The deny list is still sitting in my settings and I couldn't tell you what else it doesn't cover. Permission rules bind to tool names, and the harness picks the tool. Am I supposed to write a rule for every shell equivalent of every built-in, and keep them current against a build that changes weekly? That's roughly what my hook is now, and I don't think it should be my job.