Cursor Ask vs Agent vs Plan: Which Mode Should You Use?

The Cursor Agent panel includes four modes that share one input box but behave differently. Ask explores without editing. Agent changes files and can run terminal commands. Plan researches your repo and produces a reviewable plan before building. Debug adds instrumentation and uses runtime logs before patching. Using Agent when you only wanted an explanation creates unwanted diffs. Using Ask when you needed a fix wastes a separate trip back to Agent.

Switch modes with Shift+Tab or the mode picker dropdown. Each mode uses its own context window. Start a new chat when you switch to an unrelated task. Full Explore coverage lives at /explore/cursor.

Modes at a glance

• Ask: read only exploration and architecture questions
• Agent: multi file edits, terminal commands, default shipping mode
• Plan: clarifying questions plus reviewable plan before build
• Debug: runtime instrumentation and log driven fixes
• Tab: inline completion while typing, separate from Agent panel

Quick comparison

• Ask: read only answers, no file edits, no terminal
• Agent: default for building, refactoring, tests, and commands
• Plan: clarifying questions, written plan, build after approval
• Debug: hypotheses, instrumentation, reproduction, targeted fix

Ask mode workflow

Use Ask when you need to understand code before changing it. The workflow is: open Ask, attach @ context for the area you care about, ask a focused question, read the answer, decide whether to switch to Agent. Ask will not modify files or run shell commands.

Ask mode:
Trace how session cookies are set from login through middleware to protected routes.
Start at src/app/login/page.tsx.
Output: numbered steps with file paths only.
Do not suggest edits.

Ask mode: @src/lib/billing/retry.ts
Explain inputs, side effects, and failure paths for billingRetry().
Then list the smallest place to add idempotency keyed by invoiceId.
Do not edit files.

Agent mode workflow

Agent is for implementation. The workflow is: state outcome and verification, attach @ files when known, review diffs as they land, run tests in session, merge only after review. See /blog/how-to-use-cursor-agent-to-build-and-refactor-code for detailed prompts.

Agent: @src/server/auth/session.ts
Implement refresh token rotation matching the pattern in session.ts.
Done when: auth.integration.test.ts passes.
Scope: src/server/auth/ only.

Plan mode workflow

Plan mode fits complex features, multi file changes, and unclear requirements. Agent asks clarifying questions, explores the repo, and writes a plan you can edit in chat or markdown. Click build only when the plan matches what you want. Plans save to your home directory by default; use Save to workspace when the team should reuse them. If the build goes wrong, revert and tighten the plan instead of long fix up threads in Agent.

Plan mode:
Add role based access for admin vs member users.
Include middleware, database migration, API authorization, and UI gating.
List risks and file paths per step.
Do not write code until I approve the plan.

Plan mode: split checkout into separate payment and fulfillment services.
Constraints: no downtime, feature flag for rollout, existing webhook signatures unchanged.
Output: phased plan with test strategy per phase.

Debug mode workflow

Debug mode fits bugs you can reproduce but cannot explain from reading code alone: timing issues, stale state, performance regressions. Agent explores, adds logging through a local debug server, asks you to reproduce, reads logs, applies a small fix, and removes instrumentation after verification. See /blog/how-to-debug-code-with-cursor.

Debug mode:
Cart total stale after removeItem until refresh.
Steps: add two items, remove one, observe total.
Expected: immediate recalculation.
Actual: stale until remount.
@src/store/cartStore.ts attached.

Tab is separate from all four modes

Tab completion runs while you type in the editor. It does not use Ask, Agent, Plan, or Debug context and ignores project rules. When you need multi file work or tests, open Agent instead. See /blog/how-to-use-cursor-tab-without-losing-control-of-your-code.

Example: onboarding on a legacy module

Day 1 Ask: map data flow in @src/legacy/import/pipeline.ts
Day 2 Plan: design safe extraction of validation into src/lib/import/
Day 3 Agent: implement phase 1 only after plan approval
Use a new chat when the task changes.

Example: production hotfix path

Agent (narrow): @src/hotfix/patch-1421.ts
Fix null deref on line shown in stack trace.
Done when: unit test in patch-1421.test.ts passes.
No refactors. No dependency upgrades.

Switching modes without losing clarity

Each mode uses its own context window. When a Plan build finishes, continue in Agent if scope is unchanged. When moving from Ask to Agent, paste key findings into the Agent prompt. When Debug finds root cause, finish the minimal patch in Debug unless the fix requires a wide refactor that belongs in Plan.

Decision guide by situation

• New to the repo and need a map: Ask first, then Agent
• One file bug with obvious cause: Agent with narrow scope
• Feature touches auth, database, and UI: Plan then Agent
• Flaky test or race condition: Debug
• Inline completion while typing: Tab, not any Agent mode

Rules and context in every mode

Project rules in .cursor/rules, AGENTS.md, user rules, and team rules apply in Ask, Agent, Plan, and Debug. They do not apply to Tab completion. @ mentions work across modes to focus attention on files and folders. Details in /blog/how-to-give-cursor-better-context-with-mentions-and-rules.

Common mistakes

• Staying in Ask when you already decided to edit files
• Using Agent for a ten file feature without Plan approval
• Using Plan for a one line typo fix
• Using Debug before you can reproduce the bug reliably
• Switching modes mid task without starting a fresh chat when context gets confused

Example: same task in three modes

Task: add pagination to GET /api/users. In Ask, trace how GET /api/products paginates today. In Plan, list files, response shape, and migration risks. In Agent, implement after scope is clear with a test command in the prompt.

Ask: explain pagination in @src/app/api/products/route.ts
Plan: design matching pagination for /api/users with same response shape
Agent: implement after plan approval; run npm test -- --testPathPattern=users

Keyboard and UI habits

Shift+Tab cycles modes quickly when you already know the next mode. The mode picker dropdown helps when you want to jump directly to Debug or Plan without cycling through others. Side chats can hold reference material while the main Agent thread stays focused on implementation.

Conversation search across past chats

Agent can search prior conversations when it needs context from an earlier decision. You can still paste the conclusion yourself when the decision was important. Do not assume Agent remembers a chat from last week unless you restate constraints.

Agent: continue the auth refactor we discussed.
Constraints carry over:
- no changes outside src/server/auth/
- tests must pass npm test -- --testPathPattern=auth
Attach @src/server/auth/session.ts as canonical pattern.

Plan mode save to workspace

Plans default to your home directory. Use Save to workspace when the plan should live in the repository for team review or future Agent sessions. Treat the saved plan like a lightweight design doc Agent must follow during build.

Plan mode: migrate auth to refresh tokens.
After plan approval, save plan to workspace under docs/plans/auth-refresh.md
Build only steps 1 and 2 in this session.

Choosing a model for the mode

You can pick a model from the Agent panel where your plan allows. Heavier models suit large refactors in Agent or Plan. Faster models suit Ask exploration. Debug benefit comes from reproduction quality more than model choice alone. Usage draws from Cursor Models pool or Other Models pool per Cursor docs depending on selection.

Related: /blog/how-to-use-cursor-agent-to-build-and-refactor-code, /blog/how-to-debug-code-with-cursor, /blog/how-to-test-and-verify-changes-made-by-cursor.