Tool Selection: Mira vs Grep/Glob

Use Mira Tools When

1. Searching for code by intent - code(action="search", query="authentication") finds auth code even if the word "authentication" isn't used
2. Understanding file structure - code(action="symbols", file_path="file.rs") lists all definitions
3. Tracing call relationships - code(action="callers", function_name="fn_name") / code(action="callees", function_name="fn_name") for actual call graph
4. Recalling past decisions - memory(action="recall", query="topic") before making architectural changes
5. Storing decisions - memory(action="remember", content="...", category="decision") after important choices

Use Grep/Glob When

1. Searching for literal strings (error messages, UUIDs, specific constants)
2. Finding files by exact filename pattern when you know the name
3. Simple one-off searches that don't need semantic understanding

Wrong vs Right

| Task | Wrong | Right | |------|-------|-------| | Find authentication code | grep -r "auth" | code(action="search", query="authentication") | | What calls this function? | grep -r "function_name" | code(action="callers", function_name="function_name") | | List functions in file | grep "fn " file.rs | code(action="symbols", file_path="file.rs") | | Use external library | Guess from training data | Context7: resolve-library-id -> query-docs | | Find config files | - | glob("**/*.toml") - OK, exact pattern | | Find error message | - | grep "error 404" - OK, literal string |

Example: "Where is authentication handled?" -> use code(action="search", query="authentication handling"), not grep -r "auth". Semantic search finds related code using different terminology.

Example: "Find where 'connection refused' is logged" -> use Grep with pattern "connection refused". Literal string searches are Grep's strength.