How-to ·

Claude Opus 5.5: How to Run and Steer Long Tasks

Claude Opus 5.5 handles long multi-step projects independently when given clear completion criteria. You receive finished code changes, clear summaries of open decisions, and audited project files with minimal manual interruptions.

By · 4 min read

In short
  • Define the completion criteria in a single initial prompt.
  • Remove thinking instructions because Claude Opus 5.5 reasons automatically before replies.
  • Configure CLAUDE.md to prevent unnecessary progress pauses during long runs.
  • Maintain task checklists in project files so progress survives context window summarization.
In this guide
  1. How to set up and run a task in Claude Opus 5.5
  2. How to prompt Claude Opus 5.5 effectively
  3. How to steer long runs in Claude Code
  4. How to check and review Claude Opus 5.5 results
  5. Common pitfalls when using Claude Opus 5.5
  6. Frequently asked questions

How to set up and run a task in Claude Opus 5.5

Setting up a long run in Claude Opus 5.5 requires defining the entire job and its finish line upfront. Providing clear completion parameters allows Claude Opus 5.5 to work for hours on multi-step tasks across large repositories with minimal oversight.

What you'll get

You end up with fully executed multi-step code migrations, test-verified changes, and an organized summary of decisions requiring your review.

  1. Hand over the complete task in your first prompt, stating the specific criteria that define when the work is finished.
  2. Remove unnecessary instructions such as 'think step by step' from your prompts or system settings.
  3. Add steering rules to your CLAUDE.md file so the tool does not halt to ask permission for non-destructive actions.
  4. Instruct Claude Opus 5.5 to track its checklist in an external file like TASKS.md.
  5. Send follow-up instructions mid-run by pressing Enter while the model is executing instead of restarting.
  6. Review the final response starting with any open blockers or decisions the model highlights.

How to prompt Claude Opus 5.5 effectively

Prompting Claude Opus 5.5 requires explicit boundaries and direct instructions rather than reasoning prompts. Because Claude Opus 5.5 decides on its own how deeply to think before every reply, traditional prompting tactics must be adjusted.

  • Define the finish line clearly: State exact conditions such as passing test suites or removing deprecated clients so the model knows when to conclude.
  • Omit reasoning requests: Remove phrases like 'think carefully' to decrease response latency without sacrificing answer quality.
  • Request direct replies for simple questions: Use the phrase 'Answer directly' or adjust the effort setting in Claude Code.
  • Exclude specific visual defaults: When requesting designs, provide an explicit list of prohibited elements such as off-white backgrounds, italic accent words, monospace labels, numbered section tags, or pill-shaped buttons.

How to steer long runs in Claude Code

Steering Claude Opus 5.5 in Claude Code centers on setting clear rules in your CLAUDE.md configuration file. Without explicit guidance, Claude Opus 5.5 can pause mid-task to offer unneeded updates or present choices that do not block progress.

Tip

Add a rule to CLAUDE.md instructing Claude Opus 5.5 to continue working when user input is not needed, while pausing before destructive operations like force-pushing or deleting data.

For extensive codebase migrations or code audits, prompt Claude Opus 5.5 to delegate duties across parallel subagents. Instruct the model to verify evidence from each subagent before accepting results and presenting a final findings table.

Long runs eventually fill the context window, causing Claude Code to summarize older conversation turns. Asking Claude Opus 5.5 to track tasks in a file like TASKS.md ensures your checklist survives context compression.

How to check and review Claude Opus 5.5 results

Checking results from Claude Opus 5.5 begins by reading any unresolved decisions or approval requests flagged at the top of the summary. Claude Opus 5.5 outlines actions taken and outstanding items in plain language.

You can standardize output by instructing CLAUDE.md to end every run under specific headings: Blocked on me, Changed, and Found. This structure ensures pending user actions are immediately visible.

Before human review, feed pull requests or diffs back into Claude Opus 5.5 to catch bugs. Early testing showed that Claude Opus 5.5 at minimum effort identifies more bugs with fewer false alarms than Opus 5 at high effort.

Note

For research or analysis tasks, explicitly prompt Claude Opus 5.5 to flag any points it could not independently confirm.

Common pitfalls when using Claude Opus 5.5

Avoiding common workflow pitfalls ensures Claude Opus 5.5 works at maximum speed and reliability. Most inefficiencies stem from using older prompt routines or failing to set automation boundaries.

Good for
  • Handing over entire end-to-end tasks with defined success criteria
  • Logging checklists in TASKS.md to survive context window summaries
  • Typing follow-up instructions into Claude Code mid-run to avoid restarts
  • Setting CLAUDE.md rules for pair programming recap formats
Not ideal for
  • Adding 'think step by step' commands that delay reply generation
  • Giving vague styling rules like 'avoid a generic look'
  • Relying on terminal scrollback rather than project files for task status
  • Allowing runs to stop repeatedly for non-blocking confirmation questions

Frequently asked questions

Do I need to ask Claude Opus 5.5 to think carefully?
No, you should remove phrases like 'think carefully' and 'think step by step' from your instructions. Claude Opus 5.5 automatically reasons before every response and chooses how much thinking is needed. Removing these lines reduces latency with no reduction in response quality.
How do I prevent Claude Opus 5.5 from pausing during long runs?
You can add a instruction to your CLAUDE.md file stating that the model should continue when user input is unnecessary. Specify that Claude Opus 5.5 should only pause for blockers or destructive actions such as deleting data or force-pushing. If prompted with 'Want me to continue?', you can simply type 'continue'.
Can I add instructions while Claude Opus 5.5 is running?
Yes, in Claude Code you can type a follow-up message and press Enter while Claude Opus 5.5 is actively executing. This prevents costly restarts on long tasks when you remember an additional requirement mid-run.
How should I structure task tracking in Claude Opus 5.5?
Ask Claude Opus 5.5 to maintain and update a checklist in a repository file such as TASKS.md. Because extended tasks can fill the context window and trigger automatic conversation summaries, maintaining a checklist in a file preserves project status.

Sources: claude.dev

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