diff --git a/src/tools/delegate-task/constants.ts b/src/tools/delegate-task/constants.ts
index b7457bcb1..3d94c90eb 100644
--- a/src/tools/delegate-task/constants.ts
+++ b/src/tools/delegate-task/constants.ts
@@ -2,6 +2,7 @@ import type {
    AvailableCategory,
    AvailableSkill,
  } from "../../agents/dynamic-agent-prompt-builder"
+import { getAgentConfigKey } from "../../shared/agent-display-names"
 import { truncateDescription } from "../../shared/truncate-description"
 export {
   CATEGORY_DESCRIPTIONS,
@@ -329,18 +330,18 @@ export function isPlanAgent(agentName: string | undefined): boolean {
 }
 
 /**
- * Plan family: plan + prometheus. Shares mutual delegation blocking only.
- * Does NOT share system prompt or task permission (only isPlanAgent controls those).
+ * Plan family: plan + prometheus. Shares mutual delegation blocking and task tool permission.
+ * Does NOT share system prompt (only isPlanAgent controls that).
  */
 export const PLAN_FAMILY_NAMES = ["plan", "prometheus"]
 
 /**
- * Check if the given agent belongs to the plan family for mutual delegation blocking.
+ * Check if the given agent belongs to the plan family (blocking + task permission).
  */
 export function isPlanFamily(category: string): boolean
 export function isPlanFamily(category: string | undefined): boolean
 export function isPlanFamily(category: string | undefined): boolean {
   if (!category) return false
-  const lowerCategory = category.toLowerCase().trim()
+  const lowerCategory = getAgentConfigKey(category).toLowerCase().trim()
   return PLAN_FAMILY_NAMES.some((name) => lowerCategory === name)
 }
diff --git a/src/tools/delegate-task/sync-continuation.ts b/src/tools/delegate-task/sync-continuation.ts
index 10bb09cdc..fa6f9f022 100644
--- a/src/tools/delegate-task/sync-continuation.ts
+++ b/src/tools/delegate-task/sync-continuation.ts
@@ -1,6 +1,6 @@
 import type { DelegateTaskArgs, ToolContextWithMetadata } from "./types"
 import type { ExecutorContext, SessionMessage } from "./executor-types"
-import { isPlanAgent } from "./constants"
+import { isPlanFamily } from "./constants"
 import { storeToolMetadata } from "../../features/tool-metadata-store"
 import { resolveCallID } from "./resolve-call-id"
 import { getTaskToastManager } from "../../features/task-toast-manager"
@@ -84,7 +84,7 @@ export async function executeSyncContinuation(
       storeToolMetadata(ctx.sessionID, callID, syncContMeta)
     }
 
-    const allowTask = isPlanAgent(resumeAgent)
+    const allowTask = isPlanFamily(resumeAgent)
     const tddEnabled = sisyphusAgentConfig?.tdd
     const effectivePrompt = buildTaskPrompt(args.prompt, resumeAgent, tddEnabled)
     const tools = {
diff --git a/src/tools/delegate-task/sync-prompt-sender.ts b/src/tools/delegate-task/sync-prompt-sender.ts
index 949ab4cc6..bd38830e5 100644
--- a/src/tools/delegate-task/sync-prompt-sender.ts
+++ b/src/tools/delegate-task/sync-prompt-sender.ts
@@ -1,6 +1,6 @@
 import type { DelegateTaskArgs, OpencodeClient, DelegatedModelConfig } from "./types"
 import type { SisyphusAgentConfig } from "../../config/schema"
-import { isPlanAgent } from "./constants"
+import { isPlanFamily } from "./constants"
 import { buildTaskPrompt } from "./prompt-builder"
 import {
   promptSyncWithModelSuggestionRetry,
@@ -64,7 +64,7 @@ export async function sendSyncPrompt(
   },
   deps: SendSyncPromptDeps = sendSyncPromptDeps
 ): Promise<string | null> {
-  const allowTask = isPlanAgent(input.agentToUse)
+  const allowTask = isPlanFamily(input.agentToUse)
   const tddEnabled = input.sisyphusAgentConfig?.tdd
   const effectivePrompt = buildTaskPrompt(input.args.prompt, input.agentToUse, tddEnabled)
   const tools = {