feat(core): optimize sub-agents system prompt intro (#18608)

packages/core/src/prompts/promptProvider.ts

@@ -132,7 +132,7 @@ export class PromptProvider {
             .getAgentRegistry()
             .getAllDefinitions()
             .map((d) => ({
-              name: d.displayName || d.name,
+              name: d.name,
               description: d.description,
             })),
         ),

packages/core/src/prompts/snippets.ts

@@ -187,11 +187,7 @@ export function renderSubAgents(subAgents?: SubAgentOptions[]): string {
   return `
 # Available Sub-Agents
 
-Sub-agents are specialized expert agents that you can use to assist you in the completion of all or part of a task.
-
-Each sub-agent is available as a tool of the same name. You MUST always delegate tasks to the sub-agent with the relevant expertise, if one is available.
-
-The following tools can be used to start sub-agents:
+Sub-agents are specialized expert agents. Each sub-agent is available as a tool of the same name. You MUST delegate tasks to the sub-agent with the most relevant expertise.
 
 <available_subagents>
 ${subAgentsXml}

packages/core/src/prompts/utils.ts

@@ -77,7 +77,7 @@ export function applySubstitutions(
       .getAgentRegistry()
       .getAllDefinitions()
       .map((d) => ({
-        name: d.displayName || d.name,
+        name: d.name,
         description: d.description,
       })),
   );