language_model: Add tool uses to message content (#17381)

This PR updates the message content for an LLM request to allow it
contain tool uses.

We need to send the tool uses back to the model in order for it to
recognize the subsequent tool results.

Release Notes:

- N/A

crates/language_model/src/language_model.rs

@@ -68,7 +68,7 @@ pub enum StopReason {
     ToolUse,
 }
 
-#[derive(Debug, PartialEq, Clone, Serialize, Deserialize)]
+#[derive(Debug, PartialEq, Eq, Hash, Clone, Serialize, Deserialize)]
 pub struct LanguageModelToolUse {
     pub id: String,
     pub name: String,

crates/language_model/src/provider/anthropic.rs

@@ -267,6 +267,9 @@ pub fn count_anthropic_tokens(
                         MessageContent::Image(image) => {
                             tokens_from_images += image.estimate_tokens();
                         }
+                        MessageContent::ToolUse(_tool_use) => {
+                            // TODO: Estimate token usage from tool uses.
+                        }
                         MessageContent::ToolResult(tool_result) => {
                             string_contents.push_str(&tool_result.content);
                         }

crates/language_model/src/request.rs

@@ -1,6 +1,7 @@
 use std::io::{Cursor, Write};
 
 use crate::role::Role;
+use crate::LanguageModelToolUse;
 use base64::write::EncoderWriter;
 use gpui::{point, size, AppContext, DevicePixels, Image, ObjectFit, RenderImage, Size, Task};
 use image::{codecs::png::PngEncoder, imageops::resize, DynamicImage, ImageDecoder};
@@ -171,6 +172,7 @@ pub struct LanguageModelToolResult {
 pub enum MessageContent {
     Text(String),
     Image(LanguageModelImage),
+    ToolUse(LanguageModelToolUse),
     ToolResult(LanguageModelToolResult),
 }
 
@@ -198,8 +200,8 @@ impl LanguageModelRequestMessage {
         let mut string_buffer = String::new();
         for string in self.content.iter().filter_map(|content| match content {
             MessageContent::Text(text) => Some(text),
-            MessageContent::Image(_) => None,
             MessageContent::ToolResult(tool_result) => Some(&tool_result.content),
+            MessageContent::ToolUse(_) | MessageContent::Image(_) => None,
         }) {
             string_buffer.push_str(string.as_str())
         }
@@ -213,10 +215,10 @@ impl LanguageModelRequestMessage {
                 .get(0)
                 .map(|content| match content {
                     MessageContent::Text(text) => text.trim().is_empty(),
-                    MessageContent::Image(_) => true,
                     MessageContent::ToolResult(tool_result) => {
                         tool_result.content.trim().is_empty()
                     }
+                    MessageContent::ToolUse(_) | MessageContent::Image(_) => true,
                 })
                 .unwrap_or(false)
     }
@@ -337,6 +339,14 @@ impl LanguageModelRequest {
                                     cache_control,
                                 })
                             }
+                            MessageContent::ToolUse(tool_use) => {
+                                Some(anthropic::RequestContent::ToolUse {
+                                    id: tool_use.id,
+                                    name: tool_use.name,
+                                    input: tool_use.input,
+                                    cache_control,
+                                })
+                            }
                             MessageContent::ToolResult(tool_result) => {
                                 Some(anthropic::RequestContent::ToolResult {
                                     tool_use_id: tool_result.tool_use_id,