# inventory_bills_update_custom_fields A write tool on the ServiceTitan MCP Server MCP server. Agent View of the PolicyLayer registry record for `inventory_bills_update_custom_fields`. HTML page: https://policylayer.com/tools/jordandalton-servicetitanmcpserver/inventory-bills-update-custom-fields ## Facts - Tool: `inventory_bills_update_custom_fields` - Server: ServiceTitan MCP Server (`jordandalton/servicetitanmcpserver`) — https://policylayer.com/tools/jordandalton-servicetitanmcpserver.md - Homepage: https://github.com/JordanDalton/ServiceTitanMcpServer - Risk category: Write (Medium risk) - Registry record: grade F, identity unverified - Server rate-limited: no - Parameters: 0 - Recommended policy verdict: Rate-limited ## Example call (MCP tools/call, JSON-RPC 2.0) ```json { "jsonrpc": "2.0", "id": 1, "method": "tools/call", "params": { "name": "inventory_bills_update_custom_fields", "arguments": {} } } ``` ## Why inventory_bills_update_custom_fields is rated Medium The tool updates custom fields on inventory bills, which is a reversible data modification operation. This falls into the Write category rather than Destructive because updates are typically reversible (can be changed again). Severity is medium because incorrect updates to billing information could cause operational issues but are not inherently destructive or financial in nature. From the tool's own definition: "Tool name 'inventory_bills_update_custom_fields' contains 'update' which indicates modification of data. The sibling tools show patterns of read operations (get, get_list) and write operations (update, adjustments_update)." ## Use case AI agents use inventory_bills_update_custom_fields to create or update resources in ServiceTitan MCP Server, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your ServiceTitan MCP Server environment. ## Recommended policy (PolicyLayer) Verdict: **Rate-limited**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches ServiceTitan MCP Server: ```json { "version": "1", "default": "deny", "tools": { "inventory_bills_update_custom_fields": { "limits": [ { "counter": "inventory_bills_update_custom_fields_rate", "window": "minute", "max": 30, "scope": "grant" } ] } } } ``` ## Other tools on ServiceTitan MCP Server (453) - `appointments_delete` — Destructive — https://policylayer.com/tools/jordandalton-servicetitanmcpserver/appointments-delete.md - `appointments_remove_hold` — Destructive — https://policylayer.com/tools/jordandalton-servicetitanmcpserver/appointments-remove-hold.md - `bulk_tags_remove_tags` — Destructive — https://policylayer.com/tools/jordandalton-servicetitanmcpserver/bulk-tags-remove-tags.md - `categories_delete` — Destructive — https://policylayer.com/tools/jordandalton-servicetitanmcpserver/categories-delete.md - `contact_methods_DeleteContactMethod` — Destructive — https://policylayer.com/tools/jordandalton-servicetitanmcpserver/contact-methods-deletecontactmethod.md - `contacts_deletecontact` — Destructive — https://policylayer.com/tools/jordandalton-servicetitanmcpserver/contacts-deletecontact.md - `contacts_deletecontactrelationship` — Destructive — https://policylayer.com/tools/jordandalton-servicetitanmcpserver/contacts-deletecontactrelationship.md - `customers_delete_contact` — Destructive — https://policylayer.com/tools/jordandalton-servicetitanmcpserver/customers-delete-contact.md - `customers_delete_note` — Destructive — https://policylayer.com/tools/jordandalton-servicetitanmcpserver/customers-delete-note.md - `customers_delete_tag` — Destructive — https://policylayer.com/tools/jordandalton-servicetitanmcpserver/customers-delete-tag.md - `DiscountAndFees_Delete` — Destructive — https://policylayer.com/tools/jordandalton-servicetitanmcpserver/discountandfees-delete.md - `equipment_delete` — Destructive — https://policylayer.com/tools/jordandalton-servicetitanmcpserver/equipment-delete.md - `estimates_delete_item` — Destructive — https://policylayer.com/tools/jordandalton-servicetitanmcpserver/estimates-delete-item.md - `gross_pay_items_delete` — Destructive — https://policylayer.com/tools/jordandalton-servicetitanmcpserver/gross-pay-items-delete.md - `invoices_delete_invoice_item` — Destructive — https://policylayer.com/tools/jordandalton-servicetitanmcpserver/invoices-delete-invoice-item.md - `jobs_cancel` — Destructive — https://policylayer.com/tools/jordandalton-servicetitanmcpserver/jobs-cancel.md - `jobs_remove_cancellation` — Destructive — https://policylayer.com/tools/jordandalton-servicetitanmcpserver/jobs-remove-cancellation.md - `locations_delete_contact` — Destructive — https://policylayer.com/tools/jordandalton-servicetitanmcpserver/locations-delete-contact.md - `locations_delete_note` — Destructive — https://policylayer.com/tools/jordandalton-servicetitanmcpserver/locations-delete-note.md - `locations_delete_tag` — Destructive — https://policylayer.com/tools/jordandalton-servicetitanmcpserver/locations-delete-tag.md - `materials_delete` — Destructive — https://policylayer.com/tools/jordandalton-servicetitanmcpserver/materials-delete.md - `non_job_appointments_delete` — Destructive — https://policylayer.com/tools/jordandalton-servicetitanmcpserver/non-job-appointments-delete.md - `purchase_orders_cancel` — Destructive — https://policylayer.com/tools/jordandalton-servicetitanmcpserver/purchase-orders-cancel.md - `purchase_orders_markup_delete` — Destructive — https://policylayer.com/tools/jordandalton-servicetitanmcpserver/purchase-orders-markup-delete.md - `receipts_cancelreceipts` — Destructive — https://policylayer.com/tools/jordandalton-servicetitanmcpserver/receipts-cancelreceipts.md - `returns_cancel` — Destructive — https://policylayer.com/tools/jordandalton-servicetitanmcpserver/returns-cancel.md - `services_delete` — Destructive — https://policylayer.com/tools/jordandalton-servicetitanmcpserver/services-delete.md - `suppressions_remove` — Destructive — https://policylayer.com/tools/jordandalton-servicetitanmcpserver/suppressions-remove.md - `team_delete` — Destructive — https://policylayer.com/tools/jordandalton-servicetitanmcpserver/team-delete.md - `technician_shifts_bulk_delete` — Destructive — https://policylayer.com/tools/jordandalton-servicetitanmcpserver/technician-shifts-bulk-delete.md - …and 423 more: https://policylayer.com/tools/jordandalton-servicetitanmcpserver.md ## For agents This record is a snapshot. Live verdicts and the full registry: - Check every server in your MCP config at once: `npx -y policylayer stack` - Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md) - Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events` --- Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=jordandalton-servicetitanmcpserver · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/jordandalton-servicetitanmcpserver