Comment by x-complexity

Setting up an LSP relies on 2 requirements to properly work:

(a) The LSP's tools being competently built & consistent, and

(b) the LLM using it having been properly trained to use LSPs in general.

Using a native tool like grep has the same 2 assumptions, but

(a) is satisfied due to ossification of grep's core features (a good thing), and

(b) is extra-satisfied because the LLM can be trained to properly use grep specifically, and not "20th variation of grep wrapped behind an LSP, but just different enough to throw curveballs".

On top of that, grep is almost always present in default Linux environments, so its presence is assumed & can be relied upon when needed.