rely primarily on inline pr feedback

mcp/prInfo.ts

@@ -1,4 +1,6 @@
+import { execSync } from "node:child_process";
 import { type } from "arktype";
+import { log } from "../utils/cli.ts";
 import { contextualize, tool } from "./shared.ts";
 
 export const PullRequestInfo = type({
@@ -7,7 +9,8 @@ export const PullRequestInfo = type({
 
 export const PullRequestInfoTool = tool({
   name: "get_pull_request",
-  description: "Retrieve minimal information for a specific pull request by number.",
+  description:
+    "Retrieve PR information and automatically prepare the repository for review by fetching and checking out the PR branch.",
   parameters: PullRequestInfo,
   execute: contextualize(async ({ pull_number }, ctx) => {
     const pr = await ctx.octokit.rest.pulls.get({
@@ -21,6 +24,20 @@ export const PullRequestInfoTool = tool({
     const baseBranch = data.base.ref;
     const headBranch = data.head.ref;
 
+    if (!baseBranch) {
+      throw new Error(`Base branch not found for PR #${pull_number}`);
+    }
+
+    // Automatically fetch and checkout branches for review
+    log.info(`Fetching base branch: origin/${baseBranch}`);
+    execSync(`git fetch origin ${baseBranch} --depth=20`, { stdio: "inherit" });
+
+    log.info(`Fetching PR branch: origin/${headBranch}`);
+    execSync(`git fetch origin ${headBranch}`, { stdio: "inherit" });
+
+    log.info(`Checking out PR branch: origin/${headBranch}`);
+    execSync(`git checkout origin/${headBranch}`, { stdio: "inherit" });
+
     return {
       number: data.number,
       url: data.html_url,