diff --git a/src/upload-lib/types.ts b/src/upload-lib/types.ts
index 64480a4fc..7282271f6 100644
--- a/src/upload-lib/types.ts
+++ b/src/upload-lib/types.ts
@@ -1,22 +1,45 @@
+/**
+ * Represents the minimum, common payload for SARIF upload endpoints that we support.
+ */
 export interface BasePayload {
+  /** The gzipped contents of a SARIF file. */
   sarif: string;
 }
 
+/**
+ * Represents the payload expected for Code Scanning and Code Quality SARIF uploads.
+ */
 export interface UploadPayload extends BasePayload {
+  /** The SHA of the commit that was analysed. */
   commit_oid: string;
+  /** The ref that was analysed. */
   ref: string;
+  /** The analysis key that identifies the analysis. */
   analysis_key?: string;
+  /** The name of the analysis. */
   analysis_name?: string;
+  /** The ID of the workflow run that performed the analysis. */
   workflow_run_id: number;
+  /** The attempt number. */
   workflow_run_attempt: number;
+  /** The URI where the repository was checked out. */
   checkout_uri: string;
+  /** The matrix value. */
   environment?: string;
+  /** A string representation of when the analysis was started. */
   started_at?: string;
+  /** The names of the tools that performed the analysis. */
   tool_names: string[];
+  /** For a pull request, the ref of the base the PR is targeting. */
   base_ref?: string;
+  /** For a pull request, the commit SHA of the merge base. */
   base_sha?: string;
 }
 
+/**
+ * Represents the payload expected for Code Scanning Risk Assessment SARIF uploads.
+ */
 export interface AssessmentPayload extends BasePayload {
+  /** The ID of the assessment for which the SARIF is for. */
   assessment_id: number;
 }