fix: strip unsupported Gemini agent skills frontmatter (#971)

bin/install.js

@@ -757,6 +757,7 @@ function stripSubTags(content) {
  * - tools: must be a YAML array (not comma-separated string)
  * - tool names: must use Gemini built-in names (read_file, not Read)
  * - color: must be removed (causes validation error)
+ * - skills: must be removed (causes validation error)
  * - mcp__* tools: must be excluded (auto-discovered at runtime)
  */
 function convertClaudeToGeminiAgent(content) {
@@ -771,11 +772,19 @@ function convertClaudeToGeminiAgent(content) {
   const lines = frontmatter.split('\n');
   const newLines = [];
   let inAllowedTools = false;
+  let inSkippedArrayField = false;
   const tools = [];
 
   for (const line of lines) {
     const trimmed = line.trim();
 
+    if (inSkippedArrayField) {
+      if (!trimmed || trimmed.startsWith('- ')) {
+        continue;
+      }
+      inSkippedArrayField = false;
+    }
+
     // Convert allowed-tools YAML array to tools list
     if (trimmed.startsWith('allowed-tools:')) {
       inAllowedTools = true;
@@ -801,6 +810,12 @@ function convertClaudeToGeminiAgent(content) {
     // Strip color field (not supported by Gemini CLI, causes validation error)
     if (trimmed.startsWith('color:')) continue;
 
+    // Strip skills field (not supported by Gemini CLI, causes validation error)
+    if (trimmed.startsWith('skills:')) {
+      inSkippedArrayField = true;
+      continue;
+    }
+
     // Collect allowed-tools/tools array items
     if (inAllowedTools) {
       if (trimmed.startsWith('- ')) {
@@ -2414,6 +2429,7 @@ function installAllRuntimes(runtimes, isGlobal, isInteractive) {
 if (process.env.GSD_TEST_MODE) {
   module.exports = {
     getCodexSkillAdapterHeader,
+    convertClaudeToGeminiAgent,
     convertClaudeAgentToCodexAgent,
     generateCodexAgentToml,
     generateCodexConfigBlock,