fix(slack): correct thread parent on cursor-resume, complete DM scope hints, reject empty suggested prompts

- get_thread_replies: identify thread parent by ts === thread_ts instead of
  assuming index 0, so cursor-resumed pages (which omit the parent) no longer
  mislabel a reply as the parent
- get_channel_history + get_thread_replies: include im:history/mpim:history in
  the missing_scope hint to match the OAuth grant and DM/MPIM reads
- set_suggested_prompts: throw a clear error when no valid prompt is provided
  instead of silently calling Slack with an empty prompts array

Author: waleedlatif1

apps/sim/tools/slack/get_channel_history.ts

@@ -113,7 +113,7 @@ export const slackGetChannelHistoryTool: ToolConfig<
       limit: params.limit ? Number(params.limit) : 200,
       cursor: params.cursor,
       maxPages: params.maxPages ? Math.max(Number(params.maxPages), 1) : DEFAULT_MAX_PAGES,
-      missingScopeHint: 'channels:history, groups:history',
+      missingScopeHint: 'channels:history, groups:history, im:history, mpim:history',
     })
 
     return {

apps/sim/tools/slack/get_thread_replies.ts

@@ -120,12 +120,16 @@ export const slackGetThreadRepliesTool: ToolConfig<
       limit: params.limit ? Number(params.limit) : 200,
       cursor: params.cursor,
       maxPages: params.maxPages ? Math.max(Number(params.maxPages), 1) : DEFAULT_MAX_PAGES,
-      missingScopeHint: 'channels:history, groups:history',
+      missingScopeHint: 'channels:history, groups:history, im:history, mpim:history',
     })
 
     const messages = result.messages
-    const parentMessage = messages.length > 0 ? messages[0] : null
-    const replies = messages.slice(1)
+    const threadTs = params.threadTs?.trim()
+    // The thread parent is the message whose ts equals the requested thread_ts.
+    // It is only present on the first page; cursor-resumed pages contain replies
+    // only, so identify the parent by ts rather than assuming index 0.
+    const parentMessage = messages.find((msg) => msg.ts === threadTs) ?? null
+    const replies = parentMessage ? messages.filter((msg) => msg !== parentMessage) : messages
 
     return {
       success: true,

apps/sim/tools/slack/set_suggested_prompts.ts

@@ -103,6 +103,11 @@ export const slackSetSuggestedPromptsTool: ToolConfig<
     }),
     body: (params: SlackSetSuggestedPromptsParams) => {
       const prompts = normalizePrompts(params.prompts).slice(0, 4)
+      if (prompts.length === 0) {
+        throw new Error(
+          'At least one suggested prompt with a non-empty "title" and "message" is required.'
+        )
+      }
       const title = params.promptsTitle?.trim()
       return {
         channel_id: params.channel?.trim(),