MarketBrief defines 7 tools with complete input schemas and descriptions. Naming follows verb_noun convention (generate_report, fetch_market_data, analyze_regime). Descriptions are substantive (100-250 chars), explaining WHAT each tool does and WHEN to use it. However, output schemas are entirely undocumented, LLMs cannot infer what fields to expect from responses. Parameter descriptions are present but lack format constraints (e.g., 'date' accepts ISO format but no pattern validation stated). No error handling guidance, no recovery paths, and no mention of API key requirements in parameter descriptions. Security concern: generate_report requires ANTHROPIC_API_KEY but does not document secret injection pattern. analyze_breadth has empty inputSchema properties, suggesting incomplete definition.

• Document output schemas for all 7 tools. Specify field names, types, and structure. Example: generate_report returns {tagline: string, focus: string, issues: [{title, analysis}], positioning_table: {...}, news_digest: [...], calendar: [...]}.
• Add JSON Schema pattern constraints to date parameters. Use 'pattern': '^\d{4}-\d{2}-\d{2}$' for ISO 8601 dates in fetch_calendar.
• Complete analyze_breadth inputSchema. Either document that it accepts no parameters (and explain why), or add optional parameters like lookback_days, threshold_pct, etc.
• Clarify secret injection for ANTHROPIC_API_KEY in generate_report. Document that the key is loaded from environment (not passed as parameter) and explain the server-side injection pattern.
• Add error handling guidance to fetch_* tools. Document fallback behavior (e.g., 'If Yahoo Finance fails, Stooq is used as fallback') and what the LLM should do if both fail.

Inferred effective spec: <=2025-11-25.

• Relies on Logging (deprecated) - log to stderr or use OpenTelemetry