Server demonstrates solid foundational quality with complete JSON Schema definitions, consistent error handling patterns, and thoughtful security-aware descriptions. All 10 tools have explicit schemas with type constraints, regex patterns, and min/max bounds. Descriptions are present and contextually appropriate (avg ~120 chars), though some lack actionable guidance for LLM selection. Tool naming follows verb_noun convention (vault_get_secret, vault_list_secrets). Key gaps: no output schemas documented, parameter descriptions sometimes generic, no idempotency guarantees stated, and destructive operations lack confirmation patterns. Error responses use structured prefixes (SECURITY_VIOLATION, MUTATION_DENIED) but don't guide recovery. Composition is clean, each tool has single responsibility, but chaining metadata is incomplete (e.g., vault_list_secrets returns secretIds but no labels/versions for downstream calls).

• Document output schemas for all tools. E.g., vault_list_secrets should specify: {secretIds: string[], pageToken?: string, total?: number}. Include field types and chaining IDs (e.g., secretId for downstream vault_get_secret calls).
• Add confirmation/dry-run pattern to destructive tools. vault_disable_version should accept a 'confirm' boolean parameter (default false) or offer a separate 'preview_disable_version' tool that shows impact before execution.
• Enhance error messages with recovery guidance. Replace 'SECURITY_VIOLATION: Access Denied' with 'Access Denied: secret does not have mcp-accessible=true label. Call vault_check_permission(secretId) to verify, or contact admin to add label.'
• Expand parameter descriptions to include constraints inline. E.g., 'reason (10-500 chars): Audit trail entry explaining why access is needed. Example: Procesar pago de factura #1234'.
• State idempotency guarantees in tool descriptions. E.g., vault_create_secret: 'Idempotent, calling twice with same secretId returns existing secret without error.' vault_add_version: 'Non-idempotent, each call creates a new version; retry with same value creates duplicate.'.