Stop guessing.
Prompt Claude right.
The only tool suite that truly understandsCLAUDE.md · SKILL.md · Subagent prompts · XML format.
Not for ChatGPT users. Built for Claude builders.
Prompt Optimizer
Transform a raw prompt into a structured Claude prompt with proper XML tags, output control, guardrails, and format enforcement.
Prompt Debugger
Analyze and fix Claude-specific bugs: XML tag errors, instruction overflow, subagent context leaks, hallucination risks, and model mismatches.
CLAUDE.md Builder
Generate project-specific CLAUDE.md files with smart budget management — always staying under the 150-instruction limit.
Coming SoonSKILL.md Generator
Generate SKILL.md files with correct Anthropic YAML frontmatter and optimized trigger descriptions for Claude auto-detection.
Paste your prompt
Anything — one line, a full system prompt, or an entire CLAUDE.md file
Pick your target type
CLAUDE.md · SKILL.md · System Prompt · Subagent Prompt · Tool Definition
Get optimized output
Quality score, token count, instruction budget — copy and ship immediately
<!-- Target: System Prompt · Model: Claude Sonnet -->
<role>
You are a data collection AI agent specialized
in scraping and analyzing Reddit content.
</role>
<task>
Collect posts from specified subreddits
and return structured JSON data.
</task>
<constraints>
- Only include publicly available posts
- Do not hallucinate missing data fields
- Return ONLY valid JSON, no prose
</constraints>
Your tools should too.
XML tags > Markdown headers
Claude follows <role> tags significantly better than ## Role headings — because it was trained on XML-heavy data. Generic prompt tools don't account for this.
The 150-instruction cliff
CLAUDE.md has a hard limit of ~150 instructions. Beyond that, Claude enters exponential degradation — silently ignoring rules in an unpredictable order. Most developers hit this limit without knowing.
Subagent amnesia
Claude subagents have zero memory of the parent conversation. Prompts that say "as we discussed" will cause hallucinations. Every subagent prompt needs to be 100% self-contained. This is the #1 beginner mistake.
Lost in the Middle
Claude recalls the beginning and end of its context window far better than the middle. Critical instructions buried in the center of a long prompt are ignored 30–40% of the time.
Haiku degrades faster
Claude Haiku starts showing instruction degradation after ~80 rules, while Sonnet holds reliably up to ~150. Using the same prompt across both models is a silent performance bug.
Code style rules burn your budget
Formatting preferences in CLAUDE.md waste 30–50 instructions unnecessarily. Move them to a linter (Prettier / ESLint) and reclaim nearly a third of your instruction budget.
Always specify the return format
If a tool description doesn't declare its return format, Claude will write incorrect parsing logic. Always include an explicit schema: {id: str, name: str}