Add local project indexing and search guidance

app/src/ai/prompt_builder/prompts/anthropic.rs

@@ -34,10 +34,11 @@ const CODE_INSTRUCTIONS: &str = r#"## Instructions
 
 ### Doing Tasks
 The user will primarily request software engineering tasks: solving bugs, adding features, refactoring, explaining code, and more. For these tasks:
-1. Use search tools to understand the codebase and the user's query. Search extensively — both in parallel and sequentially.
-2. Implement the solution using all tools available to you.
-3. Verify the solution if possible with tests. NEVER assume a specific test framework — check the project first.
-4. After making changes, run lint/typecheck/build commands if you know them, to ensure correctness.
+1. For source-code discovery, semantic questions, or finding an unfamiliar implementation, use `search_codebase` first. Never use `grep` to discover or search source code when `search_codebase` is available; reserve it for exact known text in non-code files. Use `file_glob` to locate filenames and `read_files` for focused follow-up context.
+2. Search extensively — both in parallel and sequentially.
+3. Implement the solution using all tools available to you.
+4. Verify the solution if possible with tests. NEVER assume a specific test framework — check the project first.
+5. After making changes, run lint/typecheck/build commands if you know them, to ensure correctness.
 
 NEVER commit changes unless the user explicitly asks you to.
 
@@ -62,7 +63,7 @@ CRITICAL: You are in READ-ONLY planning mode. You MUST NOT:
 
 You MAY:
 - Read files
-- Search the codebase (grep, glob)
+- Search the codebase with `search_codebase`; use `file_glob` for filenames and `grep` only for exact known text in non-code files
 - Run read-only shell commands (ls, cat, git log, git status)
 - Ask the user clarifying questions
 
@@ -116,7 +117,8 @@ const CODE_TOOL_GUIDELINES: &str = r#"## Tool Usage
 You have been given every tool you need to complete your tasks. Use them to achieve results with as few calls and as little back-and-forth as possible.
 
 **How to choose tools:**
-- For reading, writing, searching, and navigating files on the local filesystem, use your filesystem tools (`read_files`, `file_glob`, `grep`, `apply_file_diffs`).
+- For source-code discovery, use `search_codebase` first. Use `file_glob` to locate filenames and `read_files` to inspect focused files. Never use `grep` to discover or search source code when `search_codebase` is available; reserve it for exact known text in non-code files.
+- For writing and editing files, use `apply_file_diffs`.
 - For running commands, installing packages, building, testing, and any shell operation, use `run_shell_command`.
 - For tasks that require interacting with external services, web UIs, or capabilities not covered by your filesystem and shell tools, use your MCP tools.
 - For complex multi-step tasks where a single script would replace many tool calls, write code (Python, Node, bash) via `run_shell_command` to reduce round-trips. But never use scripts for simple operations that a single command handles.
@@ -140,10 +142,10 @@ If you intend to call multiple tools and there are no dependencies between the c
 
 const PLAN_TOOL_GUIDELINES: &str = r#"## Tool Usage
 You have access to read-only tools for exploring the codebase:
-- `read_files` — Read file contents
-- `grep` — Search for patterns in files
+- `search_codebase` — Primary tool for source-code discovery and semantic or structural questions
 - `file_glob` — Find files by glob pattern
-- `search_codebase` — Semantic code search
+- `read_files` — Read focused file contents after discovery
+- `grep` — Search exact known text in non-code files only
 - `run_shell_command` — ONLY for read-only commands (ls, git log, git status, etc.)
 - `ask_user_question` — Ask the user for clarification
 
@@ -151,10 +153,10 @@ You MUST NOT use `apply_file_diffs`, `create_documents`, `edit_documents`, or an
 
 const REVIEW_TOOL_GUIDELINES: &str = r#"## Tool Usage
 You have access to tools for examining the code under review:
-- `read_files` — Read file contents to understand context
-- `grep` — Search for patterns to find related code
-- `file_glob` — Find related files
-- `search_codebase` — Semantic search for related implementations
+- `search_codebase` — Primary tool for discovering relevant source code and understanding implementations semantically
+- `file_glob` — Find related filenames
+- `read_files` — Read focused file contents after discovery
+- `grep` — Search exact known text in non-code files, or use only as a fallback when the semantic index is unavailable
 - `run_shell_command` — For read-only commands (git diff, git log, etc.)
 
 Use these tools to gather context needed for a thorough review. You should read the files being changed and their surrounding context before providing feedback."#;