Updated the layout of the tools section

fern/assistants/end-call-phrases.mdx

@@ -91,6 +91,6 @@ See [call end reasons](/calls/call-ended-reason) for the complete list of ended
 
 ## Related
 
-- [Built-in call tools](/tools/default-tools)
+- [Built-in tools](/tools/default-tools)
 - [Call end reasons](/calls/call-ended-reason)
 - [Troubleshoot call errors](/calls/troubleshoot-call-errors)

fern/assistants/examples/appointment-scheduling.mdx

@@ -101,7 +101,7 @@ Use the Google Calendar integration for availability and booking, or your own AP
 
 <Tabs>
   <Tab title="Use Google Calendar (recommended)">
-    See: [Google Calendar Integration](/tools/google-calendar)
+    See: [Google Calendar](/tools/google-calendar)
 
     Configure tools for:
     - `check_availability(service, date)`
@@ -110,7 +110,7 @@ Use the Google Calendar integration for availability and booking, or your own AP
     - `cancel_appointment(appointmentId)`
   </Tab>
   <Tab title="Custom tools (HTTP)">
-    See: [Custom Tools](/tools/custom-tools)
+    See: [Function tools](/tools/custom-tools)
 
     Define function tools that call your scheduling backend. Attach CSV knowledge bases (customers/services) if using the sample data above.
   </Tab>
@@ -281,6 +281,6 @@ Repeat critical scenarios before release. A tool mock checks behavior under a su
 
 ## Next steps
 
-- **Tools**: [Google Calendar](/tools/google-calendar), [Custom Tools](/tools/custom-tools)
+- **Tools**: [Google Calendar](/tools/google-calendar), [Function tools](/tools/custom-tools)
 - **Structured outputs**: [Extract structured data](/assistants/structured-outputs-quickstart)
 - **Multichannel**: [Web integration](/quickstart/web)

fern/assistants/examples/inbound-support.mdx

@@ -978,7 +978,7 @@ Just like that, you've built a 24/7 customer support hotline that can handle inb
 
 Consider the reading the following guides to further enhance your assistant:
 
-* [**Knowledge Bases**](/knowledge-base) - Learn more about knowledge bases to build knowledge-based agents.
+* [**Knowledge bases**](/knowledge-base) - Learn more about knowledge bases to build knowledge-based agents.
 * [**External Integrations**](../tools/) - Configure integrations with [Google Calendar](../tools/google-calendar), [Google Sheets](../tools/google-sheets), [Slack](../tools/slack), etc.
 * [**Squads**](/squads) - Learn how to compose multiple assistants and transfer seamlessly for complex use cases.
 

fern/assistants/examples/lead-qualification.mdx

@@ -73,7 +73,7 @@ Configure function tools or your CRM API for:
 - `update_crm(leadId, callOutcome, nextSteps)`
 - `book_meeting(prospect, time)`
 
-See [Custom Tools](/tools/custom-tools) and [Google Calendar](/tools/google-calendar).
+See [Function tools](/tools/custom-tools) and [Google Calendar](/tools/google-calendar).
 
 ---
 
@@ -166,7 +166,7 @@ Create a phone number or trigger an outbound call. See [Phone calls](/quickstart
 
 ## Next steps
 
-- **CRM integration**: Connect your CRM via [Custom Tools](/tools/custom-tools)
+- **CRM integration**: Connect your CRM via [Function tools](/tools/custom-tools)
 - **Calendar**: [Google Calendar](/tools/google-calendar)
 - **Escalation**: Use a [Squad](/squads) to hand off to a specialized closer
 

fern/assistants/examples/multilingual-agent.mdx

@@ -1047,7 +1047,7 @@ Consider reading the following guides to further enhance your multilingual imple
 
 * [**Squad-based Multilingual Support**](/squads/examples/multilingual-support) - Compare with structured language selection approach
 * [**Multilingual Configuration Guide**](/customization/multilingual) - Learn about all multilingual configuration options
-* [**Custom Tools**](/tools/custom-tools) - Build advanced multilingual tools and integrations
+* [**Function tools**](/tools/custom-tools) - Build advanced multilingual tools and integrations
 
 <Callout>
 Need help with multilingual implementation? Chat with the team on our [Discord](https://discord.com/invite/pUFNcf2WmH) or mention us on [X/Twitter](https://x.com/Vapi_AI).

fern/assistants/examples/support-escalation.mdx

@@ -992,5 +992,5 @@ async function getEscalationWithQueueManagement(context: any) {
 You've built a sophisticated customer support escalation system using assistants! Consider these enhancements:
 
 * **[Call Analysis](/assistants/call-analysis)** - Analyze escalation patterns and optimize routing
-* **[Custom Tools](/tools/custom-tools)** - Build additional tools for advanced support logic
+* **[Function tools](/tools/custom-tools)** - Build additional tools for advanced support logic
 * **[Webhooks](/server-url)** - Learn more about webhook security and advanced event handling 

fern/assistants/flush-syntax.mdx

@@ -232,4 +232,4 @@ Now that you understand flush syntax:
 
 - **[Voice formatting plan](/assistants/voice-formatting-plan):** Control voice output formatting and timing
 - **[Background messages](/assistants/background-messages):** Send messages during conversations
-- **[Custom tools](/tools/custom-tools):** Build tools that benefit from flush syntax feedback
+- **[Function tools](/tools/custom-tools):** Build tools that benefit from flush syntax feedback

fern/assistants/keypad-input-settings.mdx

@@ -81,5 +81,5 @@ Keypad input does not have a dedicated call-ended reason. Review the call transc
 ## Related
 
 - [PCI compliance](/security-and-privacy/pci)
-- [Built-in call tools](/tools/default-tools)
+- [Built-in tools](/tools/default-tools)
 - [IVR navigation](/ivr-navigation)

fern/assistants/quickstart.mdx

@@ -269,7 +269,7 @@ Call the phone number you created. Your assistant answers with its configured fi
 
 ## Next steps
 
-- **Add tools**: [Custom tools](/tools/custom-tools)
+- **Add tools**: [Function tools](/tools/custom-tools)
 - **Tune speech**: [Speech configuration](/customization/speech-configuration)
 - **Use a preset**: [Model Intelligence presets](/assistants/model-intelligence/presets) bundle a transcriber, model, and voice for common use cases.
 - **Structure data**: [Structured outputs](/assistants/structured-outputs)

fern/assistants/structured-outputs.mdx

@@ -849,6 +849,6 @@ if (data.result === null) {
 ## Related
 
 - [Call analysis](/assistants/call-analysis) - Summarize and evaluate calls
-- [Custom tools](/tools/custom-tools) - Trigger actions during calls
+- [Function tools](/tools/custom-tools) - Trigger actions during calls
 - [Webhooks](/server-url) - Receive extracted data via webhooks
 - [Variables](/assistants/dynamic-variables) - Use dynamic data in conversations

fern/calls/assistant-based-warm-transfer.mdx

@@ -7,7 +7,7 @@ slug: calls/assistant-based-warm-transfer
 
 Assistant-based warm transfer places the customer on hold while a transfer assistant calls the destination. The transfer assistant can give the operator context, confirm that a person is ready, and then complete or cancel the transfer.
 
-Use this mode when the destination must accept the call or receive context before speaking with the customer. For a direct transfer without an operator conversation, use the [transfer call tool](/tools/transfer-call) with its default blind-transfer mode.
+Use this mode when the destination must accept the call or receive context before speaking with the customer. For a direct transfer without an operator conversation, use the [Transfer Call tool](/tools/transfer-call) with its default blind-transfer mode.
 
 ## Prerequisites
 
@@ -202,7 +202,7 @@ In **Logs → Call Logs**, inspect the original call, destination call leg, tran
 | The customer cannot continue after a failed transfer | `fallbackPlan.endCallEnabled` is `true` | Set it to `false` so the original assistant remains on the call. |
 | The transfer ends during a long operator interaction | A duration or silence timeout is too short | Increase `maxDurationSeconds` or `silenceTimeoutSeconds` within the supported ranges. |
 
-Check **Logs → API Logs** for validation and transfer errors. If Vapi initiated the transfer but the destination never rings, inspect the telephony provider's call detail records and follow [Troubleshoot call forwarding drops](/calls/troubleshoot-call-forwarding-drops).
+Check **Logs → API Logs** for validation and transfer errors. If Vapi initiated the transfer but the destination never rings, inspect the telephony provider's call detail records and follow [Troubleshoot call forwarding drops](/phone-calling/in-call-control/transfer-calls/debug-forwarding-drops).
 
 ## API reference
 
@@ -211,7 +211,7 @@ The [Create Tool API reference](/api-reference/tools/create) documents transfer
 ## Related guides
 
 <CardGroup cols={2}>
-  <Card title="Transfer call tool" icon="fa-light fa-phone-arrow-right" href="/tools/transfer-call">
+  <Card title="Transfer Call tool" icon="fa-light fa-phone-arrow-right" href="/tools/transfer-call">
     Create a transfer call tool and configure its destinations.
   </Card>
   <Card title="Warm transfer" icon="fa-light fa-comments" href="/tools/transfer-call/warm-transfer">
@@ -220,7 +220,7 @@ The [Create Tool API reference](/api-reference/tools/create) documents transfer
   <Card title="Dynamic call transfers" icon="fa-light fa-route" href="/calls/call-dynamic-transfers">
     Choose a transfer destination at runtime.
   </Card>
-  <Card title="Troubleshoot forwarding drops" icon="fa-light fa-screwdriver-wrench" href="/calls/troubleshoot-call-forwarding-drops">
+  <Card title="Troubleshoot forwarding drops" icon="fa-light fa-screwdriver-wrench" href="/phone-calling/in-call-control/transfer-calls/debug-forwarding-drops">
     Diagnose failed or incomplete transfers.
   </Card>
 </CardGroup>

fern/calls/call-dynamic-transfers.mdx

@@ -567,6 +567,6 @@ sequenceDiagram
 
 ## Related Documentation
 
-* **[Transfer call tool](/tools/transfer-call)** - Static transfer options and transfer plans
+* **[Transfer Call tool](/tools/transfer-call)** - Static transfer options and transfer plans
 * **[Webhooks](/server-url)** - Webhook security and event handling patterns
-* **[Custom Tools](/tools/custom-tools)** - Build custom tools for advanced routing logic
+* **[Function tools](/tools/custom-tools)** - Build function tools for advanced routing logic

fern/calls/troubleshoot-call-forwarding-drops.mdx

@@ -303,7 +303,7 @@ Now that you can debug call forwarding drops:
 - **Review SIP setup:** Ensure your SIP configuration follows our [advanced SIP guide](https://docs.vapi.ai/advanced/sip/sip-trunk)
 
 <CardGroup cols={2}>
-  <Card title="Transfer call tool" icon="fa-light fa-phone-arrow-right" href="/tools/transfer-call">
+  <Card title="Transfer Call tool" icon="fa-light fa-phone-arrow-right" href="/tools/transfer-call">
     Create a transfer call tool and configure its destinations.
   </Card>
   <Card title="Blind transfer" icon="fa-light fa-phone" href="/tools/transfer-call/blind-transfer">

fern/chat/session-management.mdx

@@ -259,7 +259,7 @@ These webhooks are useful for tracking session lifecycle, managing session state
 
 * **[Streaming responses](/chat/streaming)** - Add real-time responses to session-managed chats
 * **[OpenAI compatibility](/chat/openai-compatibility)** - Use familiar OpenAI patterns with sessions
-* **[Custom tools](/tools/custom-tools)** - Give assistants access to external APIs within sessions
+* **[Function tools](/tools/custom-tools)** - Give assistants access to external APIs within sessions
 
 <Callout>
 Need help? Chat with the team on our [Discord](https://discord.com/invite/pUFNcf2WmH) or mention us on [X/Twitter](https://x.com/Vapi_AI).

fern/chat/web-widget.mdx

@@ -462,7 +462,7 @@ Enhance your widget integration:
 
 * **[Chat API](/chat/quickstart)** - Build custom chat interfaces using the API directly
 * **[Voice calls](/calls/outbound-calling)** - Add programmatic voice calling capabilities
-* **[Custom tools](/tools/custom-tools)** - Give your assistant access to external APIs
+* **[Function tools](/tools/custom-tools)** - Give your assistant access to external APIs
 * **[Assistant customization](/assistants)** - Fine-tune your assistant's behavior
 
 <Tip>

fern/docs.yml

@@ -209,27 +209,30 @@ navigation:
             collapsed: true
             icon: fa-light fa-toolbox
             contents:
-              - page: API Request vs Function
-                path: tools/api-request-vs-function.mdx
-                icon: fa-light fa-code-compare
-              - page: Built-in call tools
+              - page: Built-in tools
                 path: tools/default-tools.mdx
                 icon: fa-light fa-gear
-              - section: API Request Tool
+              - page: When to use API Request or Function tools
+                path: tools/api-request-vs-function.mdx
+                icon: fa-light fa-code-compare
+              - section: API Request tool
                 path: tools/api-request.mdx
                 icon: fa-light fa-globe
                 contents:
                   - page: Coffee-order quickstart
                     path: tools/api-request/quickstart.mdx
-                  - page: Configure requests
+                  - page: Customize requests
                     path: tools/api-request/configuration.mdx
                   - page: Handle latency and retries
                     path: tools/api-request/reliability.mdx
                   - page: Handle responses and errors
                     path: tools/api-request/response-handling.mdx
                   - page: Use response data
                     path: tools/api-request/response-data.mdx
-              - section: Transfer call tool
+              - page: Function tools
+                path: tools/custom-tools.mdx
+                icon: fa-light fa-screwdriver-wrench
+              - section: Transfer Call tool
                 path: tools/transfer-call.mdx
                 icon: fa-solid fa-phone
                 contents:
@@ -239,28 +242,45 @@ navigation:
                     path: tools/transfer-call/warm-transfer.mdx
                   - page: Assistant-based warm transfer
                     path: calls/assistant-based-warm-transfer.mdx
-              - page: Voicemail tool
+              - section: Handoff tool
+                path: squads/handoff.mdx
+                icon: fa-light fa-hand-holding-hand
+                contents:
+                  - page: Configure handoff destinations
+                    path: squads/handoff/destinations.mdx
+                  - page: Pass context and variables
+                    path: squads/handoff/context-and-variables.mdx
+                  - page: Configure messages and rejection rules
+                    path: squads/handoff/messages-and-rejection.mdx
+                  - page: Troubleshoot handoffs
+                    path: squads/handoff/troubleshooting.mdx
+              - section: Voicemail tool
                 path: tools/voicemail-tool.mdx
                 icon: fa-light fa-voicemail
-              - page: Custom (Function) tools
-                path: tools/custom-tools.mdx
-                icon: fa-light fa-screwdriver-wrench
+                contents:
+                  - page: Configure the Voicemail tool
+                    path: tools/voicemail-tool/configure.mdx
               - page: Client-side tools (Web SDK)
                 path: tools/client-side-websdk.mdx
                 icon: fa-light fa-browser
-              - page: Tool rejection plan
-                path: tools/tool-rejection-plan.mdx
-                icon: fa-light fa-shield-xmark
-              - page: Static variables and aliases
-                path: tools/static-variables-and-aliases.mdx
-                icon: fa-light fa-arrow-right-arrow-left
-              - page: Custom tools troubleshooting
-                path: tools/custom-tools-troubleshooting.mdx
-                icon: fa-light fa-wrench
-              - link: Handoff tool
-                href: /squads/handoff
-                icon: fa-light fa-hand-holding-hand
-              - section: External tools
+              - section: Knowledge bases
+                path: knowledge-base/knowledge-base.mdx
+                icon: fa-light fa-book
+                contents:
+                  - page: Query tool
+                    path: knowledge-base/using-query-tool.mdx
+                    icon: fa-light fa-magnifying-glass
+                  - page: Custom knowledge base
+                    path: knowledge-base/custom-knowledge-base.mdx
+                    icon: fa-light fa-server
+                  - page: Implement the custom endpoint
+                    path: knowledge-base/implement-custom-endpoint.mdx
+                    icon: fa-light fa-code
+              - link: MCP tools
+                href: /tools/mcp
+                icon: fa-light fa-network-wired
+              - section: Integrations
+                path: tools/integrations.mdx
                 icon: fa-light fa-cubes
                 contents:
                   - page: Google Calendar
@@ -275,19 +295,27 @@ navigation:
                   - page: GoHighLevel
                     path: tools/go-high-level.mdx
                     icon: fa-light fa-arrow-up
-              - section: Knowledge retrieval
-                path: knowledge-base/knowledge-base.mdx
-                icon: fa-light fa-book
+              - section: Static variables and aliases
+                path: tools/static-variables-and-aliases.mdx
+                icon: fa-light fa-arrow-right-arrow-left
                 contents:
-                  - page: Query tool
-                    path: knowledge-base/using-query-tool.mdx
-                    icon: fa-light fa-magnifying-glass
-                  - page: Custom knowledge base
-                    path: knowledge-base/custom-knowledge-base.mdx
-                    icon: fa-light fa-server
+                  - page: How tool variables work
+                    path: tools/static-variables-and-aliases/how-variables-work.mdx
+                  - page: Set static parameters
+                    path: tools/static-variables-and-aliases/static-parameters.mdx
+                  - page: Extract and chain values
+                    path: tools/static-variables-and-aliases/extract-and-chain.mdx
+                  - page: Troubleshoot tool variables
+                    path: tools/static-variables-and-aliases/troubleshooting.mdx
+              - page: Tool rejection plan
+                path: tools/tool-rejection-plan.mdx
+                icon: fa-light fa-shield-xmark
               - page: Argument encryption
                 path: tools/arguments-encryption.mdx
                 icon: fa-light fa-lock
+              - page: Troubleshoot tools
+                path: tools/custom-tools-troubleshooting.mdx
+                icon: fa-light fa-wrench
           - page: Custom keywords
             path: customization/custom-keywords.mdx
             icon: fa-light fa-bullseye
@@ -533,9 +561,18 @@ navigation:
           - page: Overview
             path: squads.mdx
             icon: fa-light fa-eye
-          - page: Handoff tool
+          - section: Handoff tool
             path: squads/handoff.mdx
             icon: fa-light fa-hand-holding-hand
+            contents:
+              - page: Configure handoff destinations
+                path: squads/handoff/destinations.mdx
+              - page: Pass context and variables
+                path: squads/handoff/context-and-variables.mdx
+              - page: Configure messages and rejection rules
+                path: squads/handoff/messages-and-rejection.mdx
+              - page: Troubleshoot handoffs
+                path: squads/handoff/troubleshooting.mdx
           - page: Passing data between assistants
             path: squads/passing-data-between-assistants.mdx
             icon: fa-light fa-share-nodes
@@ -1025,6 +1062,8 @@ redirects:
     destination: "/test/simulations-best-practices#choose-chat-or-voice-deliberately"
   - source: /tools/code-tool
     destination: /tools/api-request
+  - source: /tools/make
+    destination: /tools/mcp
   - source: /security-and-privacy/retrieve-call-artifacts
     destination: /assistants/retrieve-call-artifacts
   - source: /developer-documentation