diff --git a/sources/glean-vnext/skills/glean_run/SKILL.md b/sources/glean-vnext/skills/glean_run/SKILL.md
index 726cbbe..26bacc2 100644
--- a/sources/glean-vnext/skills/glean_run/SKILL.md
+++ b/sources/glean-vnext/skills/glean_run/SKILL.md
@@ -116,7 +116,7 @@ run_tool({
 Constraints:
 - Paths must be absolute.
 - A key in `file_args` must not also appear in `arguments`.
-- Each file must be ≤ 1 MB (override via `GLEAN_FILE_ARG_MAX_BYTES`).
+- Each file must be ≤ 5 MB (override via `GLEAN_FILE_ARG_MAX_BYTES`).
 
 ## Rules
 
diff --git a/sources/glean-vnext/src/index.ts b/sources/glean-vnext/src/index.ts
index 051e23a..f33642a 100644
--- a/sources/glean-vnext/src/index.ts
+++ b/sources/glean-vnext/src/index.ts
@@ -245,7 +245,7 @@ const RUN_TOOL_TOOL: Tool = {
           "string. Use this to keep large values out of the inline call — " +
           "long-form text (Slack message bodies, Confluence pages, doc " +
           "contents) or a large structured argument (e.g. an agent spec). " +
-          "Paths must be absolute. Each file must be ≤ 1 MB (override " +
+          "Paths must be absolute. Each file must be ≤ 5 MB (override " +
           "via GLEAN_FILE_ARG_MAX_BYTES). A key in `file_args` must not " +
           "also appear in `arguments`.",
         additionalProperties: { type: "string" },
diff --git a/sources/glean-vnext/src/tools/run-tool.ts b/sources/glean-vnext/src/tools/run-tool.ts
index d313a70..59fd2c5 100644
--- a/sources/glean-vnext/src/tools/run-tool.ts
+++ b/sources/glean-vnext/src/tools/run-tool.ts
@@ -9,7 +9,7 @@ import { callRemoteTool } from "../remote-client.js";
 import { buildCompactArgs, writeApprovalArgsFile } from "./approval-args.js";
 import { resolveSessionId } from "../session-id.js";
 
-const DEFAULT_FILE_ARG_MAX_BYTES = 1 * 1024 * 1024;
+const DEFAULT_FILE_ARG_MAX_BYTES = 5 * 1024 * 1024;
 
 // How long a user has to respond to an approval prompt. The MCP SDK's own
 // request timeout is 60s and, on expiry, elicitInput REJECTS — so unless we