TossInbox has 8 tools with basic descriptions and input schemas, but significant gaps in parameter documentation and output schema clarity. Tool names are action-oriented (spawn, list, read, wait, remove, clear) which is good. However, most parameter descriptions are minimal (10-30 chars), falling well below the 72-char baseline. No output schemas are documented. Error handling guidance is absent. The 'spawn' tool has a confusing 'failover' parameter default (true) that contradicts the description ('fail if chosen provider is down'). Parameter relationships (e.g., 'save' directory structure) are undocumented. No tool annotations (readOnlyHint, destructiveHint) despite clear risk levels. Overall, definitions are skeletal, functional but not LLM-optimized.

• Document output schemas for all tools. Example: spawn should return {address: string, provider: string, expiresAt?: string, token?: string}. list should return {messages: [{id, from, subject, date}], total: number}.
• Expand parameter descriptions to 50-150 chars with format/constraint hints. E.g., 'timeout: give up after this many seconds (1-600, default 120). Useful for slow networks or waiting for delayed emails.'
• Add tool annotations via MCP SDK: mark 'remove' and 'clear' with destructiveHint=true; mark read-only tools with readOnlyHint=true. This enables safer agent planning.
• Clarify the 'failover' parameter: rename to 'strict_provider' or 'require_provider' and invert logic (default=false means 'allow failover'). Document: 'If true, fail immediately if the chosen provider is unavailable. If false, automatically try other providers.'
• Add error recovery guidance in descriptions. E.g., wait: 'If timeout is reached, try increasing timeout or checking the sender address. If inbox is expired, call spawn() to create a new one.'