diff --git a/packages/core/src/core/__snapshots__/prompts.test.ts.snap b/packages/core/src/core/__snapshots__/prompts.test.ts.snap
index 4e66e3403c4..099a3ffb3e3 100644
--- a/packages/core/src/core/__snapshots__/prompts.test.ts.snap
+++ b/packages/core/src/core/__snapshots__/prompts.test.ts.snap
@@ -532,11 +532,7 @@ exports[`Core System Prompt (prompts.ts) > should append userMemory with separat
 
 # 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>
   <subagent>
@@ -1331,11 +1327,7 @@ exports[`Core System Prompt (prompts.ts) > should include correct sandbox instru
 
 # 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>
   <subagent>
@@ -1454,11 +1446,7 @@ exports[`Core System Prompt (prompts.ts) > should include correct sandbox instru
 
 # 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>
   <subagent>
@@ -1577,11 +1565,7 @@ exports[`Core System Prompt (prompts.ts) > should include correct sandbox instru
 
 # 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>
   <subagent>
@@ -1808,15 +1792,11 @@ exports[`Core System Prompt (prompts.ts) > should include sub-agents in XML for
 
 # 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>
   <subagent>
-    <name>Test Agent</name>
+    <name>test-agent</name>
     <description>A test agent description</description>
   </subagent>
 </available_subagents>
@@ -2039,11 +2019,7 @@ exports[`Core System Prompt (prompts.ts) > should return the base prompt when us
 
 # 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>
   <subagent>
@@ -2158,11 +2134,7 @@ exports[`Core System Prompt (prompts.ts) > should return the base prompt when us
 
 # 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>
   <subagent>
@@ -2388,11 +2360,7 @@ exports[`Core System Prompt (prompts.ts) > should use chatty system prompt for p
 
 # 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>
   <subagent>
@@ -2507,11 +2475,7 @@ exports[`Core System Prompt (prompts.ts) > should use chatty system prompt for p
 
 # 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>
   <subagent>
diff --git a/packages/core/src/core/prompts.test.ts b/packages/core/src/core/prompts.test.ts
index 5307c3235a7..67042dfc0f1 100644
--- a/packages/core/src/core/prompts.test.ts
+++ b/packages/core/src/core/prompts.test.ts
@@ -178,7 +178,7 @@ describe('Core System Prompt (prompts.ts)', () => {
     expect(prompt).toContain('# Available Sub-Agents');
     expect(prompt).toContain('<available_subagents>');
     expect(prompt).toContain('<subagent>');
-    expect(prompt).toContain('<name>Test Agent</name>');
+    expect(prompt).toContain('<name>test-agent</name>');
     expect(prompt).toContain(
       '<description>A test agent description</description>',
     );
diff --git a/packages/core/src/prompts/promptProvider.ts b/packages/core/src/prompts/promptProvider.ts
index 1e6ee4206f6..37ca51bcc46 100644
--- a/packages/core/src/prompts/promptProvider.ts
+++ b/packages/core/src/prompts/promptProvider.ts
@@ -120,7 +120,7 @@ export class PromptProvider {
             .getAgentRegistry()
             .getAllDefinitions()
             .map((d) => ({
-              name: d.displayName || d.name,
+              name: d.name,
               description: d.description,
             })),
         ),
diff --git a/packages/core/src/prompts/snippets.ts b/packages/core/src/prompts/snippets.ts
index 2a713afbed1..76b7363c869 100644
--- a/packages/core/src/prompts/snippets.ts
+++ b/packages/core/src/prompts/snippets.ts
@@ -175,11 +175,7 @@ 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}
diff --git a/packages/core/src/prompts/utils.ts b/packages/core/src/prompts/utils.ts
index edb95c5080b..768aaf1720a 100644
--- a/packages/core/src/prompts/utils.ts
+++ b/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,
       })),
   );