Server has 7 tools with basic schemas and descriptions, but significant gaps limit production readiness. All tools have descriptions (10-100 chars, mostly adequate), and input schemas are present with type definitions. However, output schemas are completely undocumented, LLMs cannot plan downstream calls or extract structured data. Error handling is minimal (generic HTTPError catch returning {status: ERROR, error_message}). No parameter validation guidance, no enum constraints for send_style, no pagination details for get_message_history despite accepting limit/offset. Tool naming is clear and verb-based (send_*, get_*, lookup_*, add_*, upload_*), but descriptions lack context on when to use each tool vs alternatives. Missing: idempotency guidance, retry semantics, rate limits, and field-level output documentation.

• Document output schema for each tool. Example for send_message: 'Returns {message_id: string, status: string, timestamp: ISO8601, recipient: string, delivery_status: string}'. This enables LLMs to chain calls and extract IDs.
• Convert send_style to an enum constraint: enum: ['invisible', 'fireworks', 'slam', 'echo', 'spotlight', 'balloons', 'confetti', 'love', 'celebration', 'heartbeat', 'lasers', 'none']. Remove from description text.
• Add pagination guidance to get_message_history: 'Returns up to limit messages (default 50, max 100). Include total_count and next_offset in response to enable pagination loops.'
• Enhance error handling: categorize errors as retryable (network timeout, rate limit) vs user-fixable (invalid phone number, missing API key) vs fatal (auth failure). Return {error_code, error_message, recovery_hint, retryable: bool}.
• Explicitly document mutually exclusive parameters in send_group_message description: 'Either to_numbers (array of up to 25 E.164 numbers) OR group_id (UUID of existing group), not both. If both provided, group_id takes precedence.'

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

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