LSP plugin made Claude Code 11% pricier on C++ fixes

A ByteAsk Research preprint reports that requiring a clangd language server made Claude Code resolve 270 of 359 C/C++ repair attempts against 275 without it, at 11% higher API cost. If you added Anthropic’s LSP plugin to save tokens on C or C++, the study found no detectable repair gain. The authors say the results apply to their configured workflow, instructions included.

The server shortened search results, but the agent read more file content and made more model calls. Re-reads made up 94% of the extra tokens.

The authors also say public C++ benchmarks leave little room to measure a navigation tool. Working from the issue text alone, without the repository, the model named every fix site for 126 of 255 issues, in two of three tries.