Three tools with clear verb-prefixed names (generate_inbox, wait_for_email, check_inbox). Descriptions are substantive (130-250 chars), explaining what each tool does and when to use it. All input parameters have type definitions and descriptions. However, output schemas are documented only via example JSON returns, not formal schema declarations. Error handling is present but minimal, no recovery guidance or error categorization. Tool composition is clean (one clear job per tool); parameters are well-constrained with min/max bounds on timeout. Missing: formal output schema documentation, detailed error scenarios, per-tool scope declarations.

• Add formal output schema documentation. Define the Email response object structure (from: string, subject: string, receivedAt: string, otp: string|null, magicLink: string|null, body: string) in the tool output description or via structured response schema.
• Implement error categorization and recovery guidance. Catch fetchEmails() errors and return: 'Timeout waiting for email (retryable, the inbox may not have received it yet)' vs. 'Invalid inbox name, did you mean: <suggestions>?' vs. 'Authentication failed, check ZERODROP_API_KEY.'
• Add tool annotations via server.tool() metadata. Mark generate_inbox, wait_for_email, check_inbox with { readOnlyHint: true, idempotentHint: true } to signal to agents that these are safe to retry and non-destructive.
• Reduce noise in generate_inbox response. Return only the inbox address and optional watch_url if explicitly requested, not in default response. Alternatively, document why watch_url is included.
• Document timeout behavior explicitly. The default 30-second wait and max 120-second timeout are enforced, but add a note: 'Emails typically arrive within seconds; timeouts indicate the inbox never received the email.'