The statement of work or service agreement, the project plan showing deliverables and phases, evidence of the company's own methodology or product being used, and a description of the reporting structure. Client confidentiality obligations may require redaction, so involve the contract owner early rather than at the end.
Reconcile the internal and client documents
Read the client-facing documents alongside the internal role description and fix anything that conflicts, particularly about who manages the employee and what is being delivered. Where redaction is needed, agree what can be shown and keep a record of what was withheld. If the client must approve any disclosure, start that conversation well before the file is due, since customer legal teams work to their own schedules.
Add one document that is often the most informative in the set and the last to be requested: the basis on which the client is billed. A fixed price for a defined deliverable describes a different arrangement from an hourly rate for a named individual's time, and the invoice tells that story more plainly than any role description. Read the pricing schedule alongside the statement of work and the internal role description, and fix any conflict before the file is assembled rather than leaving three documents to be reconciled by someone else.
Hypothetical example: a customs classification systems specialist's engagement is described internally as delivering a configured system, while the client is invoiced monthly for the individual's days, and that discrepancy is the first thing to resolve because it goes to what the arrangement actually is.