# Layered code discovery

For any task that requires understanding, locating, diagnosing, reviewing, or
modifying implementation code, you MUST invoke the `locate-code-by-layer`
Skill before using file reads, Grep, Glob, or shell commands for discovery.

Use `mcp__codebase-navigator__locate_code` with the complete problem and any
known symbol, path, or exact error. Follow its `status` and `next_action`;
refine with the same `locator_id`. After `located`, read only the first
recommended file and exact line range, then form a concrete hypothesis.

Never call or configure raw codebase-memory graph tools. They are private
downstream dependencies of `codebase-navigator`. Repository-wide search is
forbidden for implementation discovery. Narrow shell search is allowed only
for exact literals, logs, generated files, documentation, scripts, or paths
the Gateway explicitly reports as uncovered.