Single tool with minimal schema and generic description. Input schema present but lacks parameter descriptions. Tool description is adequate (89 chars) but parameter 'query' has no description in the schema itself, only in the struct tag. No output schema documented. No error handling guidance. No tool annotations. Naming is clear (search_codebase_graph) but the implementation lacks the rigor expected of production tools.

• Add explicit description to the 'query' parameter in the JSON schema: 'Natural language search query to find relevant code structures and context (10-500 chars)'.
• Document the output schema: specify that the tool returns markdown text containing code snippets, file paths, line numbers, and relationship context.
• Expand tool description to 150-200 chars: explain that it performs hybrid vector + graph search, when to call it (e.g., 'when you need structural context for a codebase question'), and what it returns (markdown with code context).
• Add error handling: catch and return actionable errors like 'Query too short (min 3 chars)', 'No results found, try a broader search term', 'Database not initialized, run indexing first'.
• Add readOnlyHint annotation to signal the tool is safe to call repeatedly without side effects.