Server has 7 tools with basic schemas and descriptions, but significant gaps prevent production use. Tool names lack consistent verb-noun structure (e.g., 'bulkUpsertContactMarkers' vs 'create_campaign'). Descriptions exist but are often vague about prerequisites, return types, and error conditions. Parameter schemas are present but lack enums for constrained values (e.g., 'dry_run' boolean, campaign names). No documented output schemas. Error handling is absent, tools will fail silently or with unhelpful messages. Security concerns: credentials embedded in MailboxDetails objects passed as parameters. No idempotency guarantees documented despite claims. Tool composition is poor, 'bulkUpsertContactMarkers' combines enrollment + distribution logic; 'start_campaign' mixes orchestration + sending.

• Standardize all tool names to snake_case verb_noun format: rename 'bulkUpsertContactMarkers' → 'enroll_contacts', 'getMailboxByEmail' → 'get_mailbox_by_email', 'getMailboxById' → 'get_mailbox_by_id'.
• Document output schemas for all tools. Example for listMailboxes: {type: 'array', items: {type: 'object', properties: {id: {type: 'number'}, email: {type: 'string'}, firstName: {type: 'string'}, lastName: {type: 'string'}, status: {type: 'string'}}}}.
• Remove credentials from MailboxDetails responses. Return only {id, email, firstName, lastName, status, domain}. Inject SMTP/IMAP credentials server-side via environment or vault.
• Add enum constraints: 'dry_run' parameter in start_campaign should be explicit boolean with description 'If true, simulate sends without actually sending emails'; 'sequence' parameter needs a schema or link to sequence template documentation.
• Add error handling guidance to descriptions. Example: 'If email not found, call listMailboxes() to see available inboxes.' Implement try-catch with actionable error messages like 'Mailbox not found for email: {email}. Available: [list]'.