diff --git a/apps/desktop/src/components/assistant-ui/tool-fallback.tsx b/apps/desktop/src/components/assistant-ui/tool-fallback.tsx
index 6f3e7edd340..1a1087f55f1 100644
--- a/apps/desktop/src/components/assistant-ui/tool-fallback.tsx
+++ b/apps/desktop/src/components/assistant-ui/tool-fallback.tsx
@@ -136,7 +136,7 @@ function ToolGlyph({ copy, icon, status }: { copy: ToolStatusCopy; icon?: string
   const node = status ? (
     statusGlyph(status, copy)
   ) : icon ? (
-    <Codicon className="text-(--ui-text-tertiary)" name={icon} size="0.875rem" />
+    <Codicon className="text-(--ui-text-tertiary)" filled name={icon} size="0.875rem" />
   ) : null
 
   return node ? <span className={TOOL_HEADER_GLYPH_WRAP_CLASS}>{node}</span> : null
diff --git a/apps/desktop/src/components/chat/code-card.tsx b/apps/desktop/src/components/chat/code-card.tsx
index 46997caa4d7..02df72ea573 100644
--- a/apps/desktop/src/components/chat/code-card.tsx
+++ b/apps/desktop/src/components/chat/code-card.tsx
@@ -46,11 +46,12 @@ function CodeCardTitle({ className, children, ...props }: React.ComponentProps<'
   )
 }
 
-function CodeCardIcon({ className, ...props }: CodiconProps) {
+function CodeCardIcon({ className, filled = true, ...props }: CodiconProps) {
   return (
     <Codicon
       className={cn('shrink-0 text-[0.875rem] leading-none text-muted-foreground', className)}
       data-slot="code-card-icon"
+      filled={filled}
       {...props}
     />
   )
diff --git a/apps/desktop/src/components/ui/codicon.tsx b/apps/desktop/src/components/ui/codicon.tsx
index b079216884c..daacd625b8a 100644
--- a/apps/desktop/src/components/ui/codicon.tsx
+++ b/apps/desktop/src/components/ui/codicon.tsx
@@ -3,16 +3,24 @@ import type * as React from 'react'
 import { cn } from '@/lib/utils'
 
 export interface CodiconProps extends React.HTMLAttributes<HTMLElement> {
+  /** Thickens outline glyphs so they read as filled at small sizes (tool rows). */
+  filled?: boolean
   name: string
   size?: number | string
   spinning?: boolean
 }
 
-export function Codicon({ className, name, size, spinning, style, ...props }: CodiconProps) {
+export function Codicon({ className, filled, name, size, spinning, style, ...props }: CodiconProps) {
   return (
     <i
       aria-hidden="true"
-      className={cn('codicon', `codicon-${name}`, spinning && 'codicon-modifier-spin', className)}
+      className={cn(
+        'codicon',
+        `codicon-${name}`,
+        spinning && 'codicon-modifier-spin',
+        filled && 'codicon-modifier-filled',
+        className
+      )}
       style={{ fontSize: size, ...style }}
       {...props}
     />
diff --git a/apps/desktop/src/styles.css b/apps/desktop/src/styles.css
index 2bd7556d848..6016ae2e18c 100644
--- a/apps/desktop/src/styles.css
+++ b/apps/desktop/src/styles.css
@@ -5,6 +5,14 @@
 @import '@vscode/codicons/dist/codicon.css';
 @custom-variant dark (&:is(.dark *));
 
+/* In-thread tool/code glyphs render codicons at ~14px. Outline icons read
+   thin at that scale; a hairline stroke on the glyph pseudo-element fills
+   them without swapping icon semantics. */
+.codicon.codicon-modifier-filled::before {
+  -webkit-text-stroke: 0.45px currentColor;
+  paint-order: stroke fill;
+}
+
 /* Sidebar sections: tall viewports give each its own scroller; compact ones
    (this variant) flatten everything into one shared scroll. See ChatSidebar. */
 @custom-variant compact (@media (max-height: 768px));