Claude’s prompt heavily pushes it towards grep. We have an internal cross repo semantic search mcp and to get Claude to consistently use it a skill and prompting was not enough. A pre tool use hook is the answer. Claude will even write one for you if you describe the problem to it :)
I ask it to write a markdown file describing how it should go about performing the task. Then have it read the file next time. Works well for things like creating tests for controller methods where there is a procedure it should follow that was probably developed over a session with several prompts and feedback on its output.