fix: only load GitHub MCP server when its tools are allowed (#124)

* fix: only load GitHub MCP server when its tools are allowed

- Add allowedTools parameter to prepareMcpConfig
- Check for mcp__github__ and mcp__github_file_ops__ tool prefixes
- Only include MCP servers when their tools are in allowed_tools
- Maintain backward compatibility when allowed_tools is not specified
- Update tests to reflect the new conditional loading behavior

This optimizes resource usage by not loading unnecessary MCP servers
when their tools are not allowed in the configuration.

Co-authored-by: ashwin-ant <ashwin-ant@users.noreply.github.com>

* fix: always load github_file_ops server regardless of allowed_tools

- Only apply conditional loading to the github MCP server
- Always load github_file_ops server as it contains essential tools
- Update tests to reflect this behavior

Co-authored-by: ashwin-ant <ashwin-ant@users.noreply.github.com>

* refactor: move allowedTools/disallowedTools parsing to parseGitHubContext

- Change allowedTools and disallowedTools from string to string[] in ParsedGitHubContext type
- Parse comma-separated environment variables into arrays in parseGitHubContext function
- Update create-prompt and install-mcp-server to use pre-parsed arrays
- Update all affected test files to use array syntax
- Eliminate duplicate parsing logic across the codebase

* style: apply prettier formatting

---------

Co-authored-by: claude[bot] <209825114+claude[bot]@users.noreply.github.com>
Co-authored-by: ashwin-ant <ashwin-ant@users.noreply.github.com>

src/create-prompt/index.ts

@@ -35,38 +35,35 @@ const BASE_ALLOWED_TOOLS = [
 ];
 const DISALLOWED_TOOLS = ["WebSearch", "WebFetch"];
 
-export function buildAllowedToolsString(customAllowedTools?: string): string {
+export function buildAllowedToolsString(customAllowedTools?: string[]): string {
   let baseTools = [...BASE_ALLOWED_TOOLS];
 
   let allAllowedTools = baseTools.join(",");
-  if (customAllowedTools) {
-    allAllowedTools = `${allAllowedTools},${customAllowedTools}`;
+  if (customAllowedTools && customAllowedTools.length > 0) {
+    allAllowedTools = `${allAllowedTools},${customAllowedTools.join(",")}`;
   }
   return allAllowedTools;
 }
 
 export function buildDisallowedToolsString(
-  customDisallowedTools?: string,
-  allowedTools?: string,
+  customDisallowedTools?: string[],
+  allowedTools?: string[],
 ): string {
   let disallowedTools = [...DISALLOWED_TOOLS];
 
   // If user has explicitly allowed some hardcoded disallowed tools, remove them from disallowed list
-  if (allowedTools) {
-    const allowedToolsArray = allowedTools
-      .split(",")
-      .map((tool) => tool.trim());
+  if (allowedTools && allowedTools.length > 0) {
     disallowedTools = disallowedTools.filter(
-      (tool) => !allowedToolsArray.includes(tool),
+      (tool) => !allowedTools.includes(tool),
     );
   }
 
   let allDisallowedTools = disallowedTools.join(",");
-  if (customDisallowedTools) {
+  if (customDisallowedTools && customDisallowedTools.length > 0) {
     if (allDisallowedTools) {
-      allDisallowedTools = `${allDisallowedTools},${customDisallowedTools}`;
+      allDisallowedTools = `${allDisallowedTools},${customDisallowedTools.join(",")}`;
     } else {
-      allDisallowedTools = customDisallowedTools;
+      allDisallowedTools = customDisallowedTools.join(",");
     }
   }
   return allDisallowedTools;
@@ -120,8 +117,10 @@ export function prepareContext(
     triggerPhrase,
     ...(triggerUsername && { triggerUsername }),
     ...(customInstructions && { customInstructions }),
-    ...(allowedTools && { allowedTools }),
-    ...(disallowedTools && { disallowedTools }),
+    ...(allowedTools.length > 0 && { allowedTools: allowedTools.join(",") }),
+    ...(disallowedTools.length > 0 && {
+      disallowedTools: disallowedTools.join(","),
+    }),
     ...(directPrompt && { directPrompt }),
     ...(claudeBranch && { claudeBranch }),
   };
@@ -636,11 +635,11 @@ export async function createPrompt(
 
     // Set allowed tools
     const allAllowedTools = buildAllowedToolsString(
-      preparedContext.allowedTools,
+      context.inputs.allowedTools,
     );
     const allDisallowedTools = buildDisallowedToolsString(
-      preparedContext.disallowedTools,
-      preparedContext.allowedTools,
+      context.inputs.disallowedTools,
+      context.inputs.allowedTools,
     );
 
     core.exportVariable("ALLOWED_TOOLS", allAllowedTools);