diff --git a/addons/internal/connector-ui/src/FilesFields.jsx b/addons/internal/connector-ui/src/FilesFields.jsx
index 30d8cb0499..d90c08d036 100644
--- a/addons/internal/connector-ui/src/FilesFields.jsx
+++ b/addons/internal/connector-ui/src/FilesFields.jsx
@@ -3,8 +3,8 @@
 // limit of the connector kind. The page shows the limit in effect with the
 // layer that sets it. The numbers come from the server; the words live here as
 // defaults, like the rest of the shared fields.
-import { Field, TextInput } from './controls'
-import { fileLimitProblem, formatBytes, previewLimit } from './connector'
+import { Field, Hint, TextInput } from './controls'
+import { fileDirection, fileLimitProblem, formatBytes, previewLimit } from './connector'
 
 export const FILES_TEXT = {
   'files.title': 'Files',
@@ -14,6 +14,12 @@ export const FILES_TEXT = {
   'files.invalid': 'Use a number greater than 0.',
   'files.tooHigh': 'The add-on allows at most {{max}} here.',
   'files.now': 'Now: {{limit}} ({{layer}}).',
+  'files.receiveHelp': 'Files that people send to the bot. A bigger file is refused, and the bot says which limit it hit.',
+  'files.sendHelp': 'Files that the agent makes and the bot sends back. A bigger file is not sent, and the bot says which limit it hit.',
+  'files.addon.off': 'This add-on does not move files in this direction, so there is nothing to set.',
+  'files.addon.declared': 'The add-on declares up to {{max}}.',
+  'files.addon.open': 'The add-on declares no limit, so the limit of the platform applies.',
+  'files.host': 'No bot can move a file above {{max}}. An administrator sets this in the settings.',
   'files.layer.owner': 'limit set for this bot',
   'files.layer.addon': 'limit of the add-on',
   'files.layer.host': 'limit of the platform',
@@ -25,16 +31,19 @@ function shown(base, saved, mib) {
   return previewLimit(base, mib) || (saved ? { bytes: saved.effective_bytes, layer: saved.layer } : null)
 }
 
-function Limit({ label, mib, onChange, base, saved, s, testId }) {
-  const problem = fileLimitProblem(mib, base?.allowed_bytes)
-  const limit = shown(base, saved, mib)
+function Limit({ label, help, mib, onChange, base, saved, s, testId }) {
+  const dir = fileDirection(base)
+  const problem = dir === 'off' ? '' : fileLimitProblem(mib, base?.allowed_bytes)
+  const limit = dir === 'off' ? null : shown(base, saved, mib)
   const error = problem === 'invalid' ? s('files.invalid') : problem === 'tooHigh' ? s('files.tooHigh', { max: formatBytes(base.allowed_bytes) }) : undefined
+  const declared = dir === 'declared' ? s('files.addon.declared', { max: formatBytes(base.declared_bytes) })
+    : dir === 'open' ? s('files.addon.open') : dir === 'off' ? s('files.addon.off') : ''
+  const now = limit ? s('files.now', { limit: formatBytes(limit.bytes), layer: s(`files.layer.${limit.layer}`) }) : ''
   return (
-    <Field label={label} error={error}
-      hint={limit ? s('files.now', { limit: formatBytes(limit.bytes), layer: s(`files.layer.${limit.layer}`) }) : undefined}>
+    <Field label={label} error={error} hint={[help, declared, now].filter(Boolean).join(' ')}>
       {(p) => (
-        <TextInput {...p} type="number" inputMode="decimal" min="0" step="any" data-testid={testId}
-          value={mib} onChange={(e) => onChange(e.target.value)} />
+        <TextInput {...p} type="number" inputMode="decimal" min="0" step="any" data-testid={testId} disabled={dir === 'off'}
+          value={dir === 'off' ? '' : mib} onChange={(e) => onChange(e.target.value)} />
       )}
     </Field>
   )
@@ -49,13 +58,15 @@ function Limit({ label, mib, onChange, base, saved, s, testId }) {
  * @param {Function} props.s     the translation function with the defaults
  */
 export default function FilesFields({ form, setForm, kind, saved, s }) {
+  const hostCeiling = kind?.host_ceiling_bytes || 0
   return (
     <fieldset className="cn-group" data-testid="connector-filelimits">
       <legend>{s('files.title')}</legend>
       <p className="dk-hint">{s('files.help')}</p>
-      <Limit label={s('files.receiveLabel')} mib={form.file_receive_mib} base={kind?.receive} saved={saved?.receive} s={s} testId="connector-file-receive"
+      {hostCeiling > 0 && <Hint>{s('files.host', { max: formatBytes(hostCeiling) })}</Hint>}
+      <Limit label={s('files.receiveLabel')} help={s('files.receiveHelp')} mib={form.file_receive_mib} base={kind?.receive} saved={saved?.receive} s={s} testId="connector-file-receive"
         onChange={(v) => setForm({ ...form, file_receive_mib: v })} />
-      <Limit label={s('files.sendLabel')} mib={form.file_send_mib} base={kind?.send} saved={saved?.send} s={s} testId="connector-file-send"
+      <Limit label={s('files.sendLabel')} help={s('files.sendHelp')} mib={form.file_send_mib} base={kind?.send} saved={saved?.send} s={s} testId="connector-file-send"
         onChange={(v) => setForm({ ...form, file_send_mib: v })} />
     </fieldset>
   )
diff --git a/addons/internal/connector-ui/src/connector.js b/addons/internal/connector-ui/src/connector.js
index 623c11898b..3fe6fe5aaa 100644
--- a/addons/internal/connector-ui/src/connector.js
+++ b/addons/internal/connector-ui/src/connector.js
@@ -172,6 +172,16 @@ export function previewLimit(base, mib) {
   return { bytes: base.effective_bytes, layer: base.layer }
 }
 
+// What the add-on declares for one direction, from the limits of the kind:
+// 'off' (it moves no file that way), 'declared' (it names a largest file),
+// 'open' (it names none, so the platform limit applies) or 'unknown' (the page
+// has no numbers yet).
+export function fileDirection(base) {
+  if (!base) return 'unknown'
+  if (!(base.effective_bytes > 0) && !(base.allowed_bytes > 0)) return 'off'
+  return base.declared_bytes > 0 ? 'declared' : 'open'
+}
+
 // A size as a person reads it: bytes, KiB, MiB, GiB or TiB, one decimal at most.
 export function formatBytes(n) {
   if (n === 1) return '1 byte'
diff --git a/addons/telegram/ui/test/connector.test.mjs b/addons/telegram/ui/test/connector.test.mjs
index b732195248..a92c97cce0 100644
--- a/addons/telegram/ui/test/connector.test.mjs
+++ b/addons/telegram/ui/test/connector.test.mjs
@@ -1,6 +1,6 @@
 import test from 'node:test'
 import assert from 'node:assert/strict'
-import { approvalForm, approvalPayload, approvalProblem, bytesToMib, canSave, connectorForm, connectorPayload, emptyConnector, fileLimitProblem, formatBytes, mibToBytes, modeText, previewLimit, senderLine } from '../../../internal/connector-ui/src/connector.js'
+import { approvalForm, approvalPayload, approvalProblem, bytesToMib, canSave, connectorForm, connectorPayload, emptyConnector, fileDirection, fileLimitProblem, formatBytes, mibToBytes, modeText, previewLimit, senderLine } from '../../../internal/connector-ui/src/connector.js'
 
 test('chat connectors: the token goes only when it was typed', () => {
   const create = connectorPayload({ ...emptyConnector(), name: ' Bot ', token: ' 1:abc ', agent_id: 'a1', allow: ['11', ' 11', '@ada_l', ''] }, 'telegram')
@@ -121,6 +121,13 @@ test('chat connectors: a typed limit can only lower the limit in effect, and nam
   assert.equal(previewLimit(null, '1'), null)
 })
 
+test('chat connectors: the page tells what the add-on declares for a direction', () => {
+  assert.equal(fileDirection(null), 'unknown')
+  assert.equal(fileDirection({ effective_bytes: 0, allowed_bytes: 0, declared_bytes: 0, layer: 'addon' }), 'off')
+  assert.equal(fileDirection({ effective_bytes: 100, allowed_bytes: 100, declared_bytes: 0, layer: 'host' }), 'open')
+  assert.equal(fileDirection({ effective_bytes: 50, allowed_bytes: 50, declared_bytes: 50, layer: 'addon' }), 'declared')
+})
+
 test('chat connectors: sizes are written in KiB and MiB', () => {
   assert.equal(formatBytes(900), '900 bytes')
   assert.equal(formatBytes(1), '1 byte')