feat: surface read bounds

packages/ui/src/components/tool-call.tsx

@@ -702,6 +702,9 @@ export default function ToolCall(props: ToolCallProps) {
     if (!state) return getRendererAction()
     if (state.status === "pending") return getRendererAction()
 
+    const customTitle = renderer().getTitle?.(rendererContext)
+    if (customTitle) return customTitle
+
     if (isToolStateRunning(state) && state.title) {
       return state.title
     }
@@ -710,9 +713,6 @@ export default function ToolCall(props: ToolCallProps) {
       return state.title
     }
 
-    const customTitle = renderer().getTitle?.(rendererContext)
-    if (customTitle) return customTitle
-
     return getToolName(toolName())
   }
 

packages/ui/src/components/tool-call/renderers/read.tsx

@@ -9,8 +9,25 @@ export const readRenderer: ToolRenderer = {
     if (!state) return undefined
     const { input } = readToolStatePayload(state)
     const filePath = typeof input.filePath === "string" ? input.filePath : ""
-    if (!filePath) return getToolName("read")
+    const offset = typeof input.offset === "number" ? input.offset : undefined
-    return `${getToolName("read")} ${getRelativePath(filePath)}`
+    const limit = typeof input.limit === "number" ? input.limit : undefined
+    const relativePath = filePath ? getRelativePath(filePath) : ""
+    const detailParts: string[] = []
+
+    if (typeof offset === "number") {
+      detailParts.push(`Offset: ${offset}`)
+    }
+
+    if (typeof limit === "number") {
+      detailParts.push(`Limit: ${limit}`)
+    }
+
+    const baseTitle = relativePath ? `${getToolName("read")} ${relativePath}` : getToolName("read")
+    if (!detailParts.length) {
+      return baseTitle
+    }
+
+    return `${baseTitle} · ${detailParts.join(" · ")}`
   },
   renderBody({ toolState, renderMarkdown }) {
     const state = toolState()