Server has well-structured tool definitions with clear naming (verb_noun pattern) and comprehensive descriptions (avg 180 chars, within baseline 194). All 6 tools have input schemas with type declarations and parameter descriptions. However, output schemas are completely undocumented, LLMs cannot predict response structure for planning. Parameters lack enums where applicable (e.g., 'orderBy' should be enum ['nome', 'id']; 'sex' should be enum ['M', 'F']). No error handling guidance, no pagination support despite tools returning potentially large lists (list_states, list_municipalities, list_aggregates). Missing actionable error messages and recovery hints. Security is adequate (read-only operations, no secrets in params), but composition could be stronger, no batch operations, no chaining IDs in responses.

• Document output schemas for all tools. Example: list_states returns [{id: number, sigla: string, nome: string, regiao: {id: number, nome: string}}]. Include field types and descriptions.
• Convert constrained parameters to enums: orderBy: enum ['nome', 'id']; sex: enum ['M', 'F']. Remove free-form string type.
• Add pagination to list_* tools: accept limit (1-100, default 20) and offset parameters; return {items: [...], total: number, hasMore: boolean}.
• Wrap error handling in callTool(). Catch fetch errors and return structured errors: {error: string, code: 'NOT_FOUND'|'INVALID_INPUT'|'RATE_LIMITED', suggestion: string}. Example: 'Municipality code "9999999" not found. Verify code is 7 digits.'
• Clarify aggregated_data 'localities' parameter: remove mention of auto-encoding; provide examples of valid formats (N1[all], N3[35], N6[3550308]) and explain that brackets are literal, not placeholders.