Server has 6 tools with explicit schemas and descriptions, but quality is uneven. Tool names lack action verbs (health_ingest, health_query are acceptable; health_watermark, health_list_tables, health_stats are weak). Descriptions are present but terse (avg ~80 chars, below 194-char baseline). Parameter descriptions exist but lack format/constraint details. No output schemas documented. Error handling is minimal, health_ingest returns {error: ...} but others have no error guidance. Security is well-designed (SQL injection prevention, identifier validation), but this doesn't offset definition gaps. No tool annotations (readOnlyHint, destructiveHint). Composition is reasonable, tools are single-purpose and chainable via table names.

• Rename tools to verb_noun pattern: health_watermark → get_watermark, health_list_tables → list_tables, health_stats → get_stats. This matches the 90% baseline of A+ tools starting with action verbs.
• Document output schemas for all tools. E.g., health_query should declare: {columns: [string], rows: [[any]], total: int}. health_stats should declare: {[table_name]: {rows: int, min_t: int|null, max_t: int|null}}.
• Add parameter constraints to health_query: 'since/until: millisecond Unix timestamp (0 - present); limit: 1 - 5000 (default 500)'. Include format hints: 'columns: comma-separated column names, e.g. "heart_rate,timestamp"'.
• Add tool annotations via FastMCP: @mcp.tool(readOnlyHint=True) for read-only tools; @mcp.tool(destructiveHint=True) for health_ingest. This signals safety to agents.
• Enhance error handling: wrap health_query, health_schema in try-except; return structured errors like {error: 'Table not found', available_tables: [...]}, {error: 'Invalid column', valid_columns: [...]}. Match the recovery-guide pattern.