diff --git a/packages/api/src/features/agent/context.test.ts b/packages/api/src/features/agent/context.test.ts
index d3a127b67..7237d4ff0 100644
--- a/packages/api/src/features/agent/context.test.ts
+++ b/packages/api/src/features/agent/context.test.ts
@@ -4,11 +4,11 @@ import { estimateTokens, pruneAgentModelContext } from "./context";
 
 const BIG_RESUME = { basics: { name: "Alice" }, sections: { summary: { content: "x".repeat(2_000) } } };
 
-function readResumeExchange(callId: string): ModelMessage[] {
+function readResumeExchange(callId: string, toolName = "read_resume"): ModelMessage[] {
 	return [
 		{
 			role: "assistant",
-			content: [{ type: "tool-call", toolCallId: callId, toolName: "read_resume", input: {} }],
+			content: [{ type: "tool-call", toolCallId: callId, toolName, input: {} }],
 		},
 		{
 			role: "tool",
@@ -16,7 +16,7 @@ function readResumeExchange(callId: string): ModelMessage[] {
 				{
 					type: "tool-result",
 					toolCallId: callId,
-					toolName: "read_resume",
+					toolName,
 					output: { type: "json", value: { id: "resume-1", data: BIG_RESUME } },
 				},
 			],
@@ -64,10 +64,23 @@ describe("pruneAgentModelContext — tier 0 (snapshot supersession)", () => {
 		const pruned = pruneAgentModelContext(messages, 1_000_000);
 
 		expect(snapshotValue(pruned[2])).not.toHaveProperty("data");
-		expect(snapshotValue(pruned[2]).note).toContain("Superseded resume snapshot");
+		expect(snapshotValue(pruned[2]).note).toContain("Superseded document snapshot");
 		expect(snapshotValue(pruned[4])).toHaveProperty("resume");
 	});
 
+	it("keeps only the last cover letter snapshot too", () => {
+		const messages = [
+			user("hi"),
+			...readResumeExchange("call-1", "read_letter"),
+			...readResumeExchange("call-2", "read_letter"),
+		];
+
+		const pruned = pruneAgentModelContext(messages, 1_000_000);
+
+		expect(snapshotValue(pruned[2])).not.toHaveProperty("data");
+		expect(snapshotValue(pruned[4])).toHaveProperty("data");
+	});
+
 	it("returns the same array reference when there is at most one snapshot", () => {
 		const messages = [user("hi"), ...readResumeExchange("call-1")];
 
diff --git a/packages/api/src/features/agent/context.ts b/packages/api/src/features/agent/context.ts
index 5eea8e108..145e4f3bb 100644
--- a/packages/api/src/features/agent/context.ts
+++ b/packages/api/src/features/agent/context.ts
@@ -8,9 +8,9 @@ import { estimateTokenCount as estimateTextTokenCount } from "tokenx";
 
 const AGENT_CONTEXT_TOKEN_BUDGET = 40_000;
 
-const SNAPSHOT_TOOL_NAMES = new Set(["read_resume", "apply_resume_patch"]);
+const SNAPSHOT_TOOL_NAMES = new Set(["read_resume", "read_letter", "apply_resume_patch"]);
 const SUPERSEDED_SNAPSHOT_NOTE =
-	"Superseded resume snapshot removed. Base further edits on the resume state in the latest read_resume or apply_resume_patch result.";
+	"Superseded document snapshot removed. Base further edits on the latest read_resume, read_letter or apply_resume_patch result.";
 const PRUNED_TOOL_RESULT_NOTE = "Older tool result pruned to fit the context budget.";
 
 type LoosePart = Record<string, unknown> & { type: string };
@@ -69,7 +69,7 @@ function isSnapshotResultPart(part: LoosePart): boolean {
 	const value = unwrapToolOutput(part.output);
 	if (!value || typeof value !== "object") return false;
 
-	return part.toolName === "read_resume" ? "data" in value : "resume" in value;
+	return part.toolName === "apply_resume_patch" ? "resume" in value : "data" in value;
 }
 
 function supersedeSnapshotPart(part: LoosePart): LoosePart {