Claude: Capabilities & Best Practices

Claude is Anthropic's family of AI assistants known for nuanced understanding, strong reasoning, and extensive context windows.

Model Versions

Key Strengths

Long Context Window

Claude handles up to 200K tokens:

• Analyze entire codebases
• Process lengthy documents
• Maintain context in long conversations
• Compare multiple files simultaneously

Here are 50,000 lines of code from our repository.
Identify all functions that interact with the database
and flag any potential SQL injection vulnerabilities.

Nuanced Instruction Following

Claude excels at complex, multi-part instructions:

Review this pull request with the following criteria:
1. Security: Flag any user input that isn't sanitized
2. Performance: Identify N+1 queries or missing indexes
3. Style: Check against our ESLint rules (attached)
4. Testing: Verify edge cases are covered

Format findings as a GitHub review comment with
inline suggestions where possible.

Strong Reasoning

Particularly good at:

• Mathematical proofs
• Logical deduction
• Code analysis
• Document comparison

Constitutional AI

Designed to be:

• Helpful
• Harmless
• Honest

Optimal Use Cases

Code Development

Claude, help me build a REST API endpoint that:
- Accepts POST requests to /api/users
- Validates email format and password strength
- Hashes the password with bcrypt
- Stores in PostgreSQL
- Returns appropriate status codes
- Includes proper error handling

Use TypeScript with Express.

Document Analysis

I'm attaching our company's legal agreement (30 pages).
Please:
1. Summarize the key obligations for each party
2. Identify any unusual or concerning clauses
3. List all deadlines and important dates
4. Compare to standard industry terms

Research Synthesis

Here are 5 research papers on transformer architectures.
Create a comparison table covering:
- Model size
- Training data
- Key innovations
- Benchmark performance
- Limitations noted

Then write a 500-word synthesis of the current state of the field.

API Usage

Basic Request

import anthropic

client = anthropic.Anthropic()

message = client.messages.create(
    model="claude-sonnet-4-20250514",
    max_tokens=1024,
    messages=[
        {"role": "user", "content": "Explain quantum computing simply."}
    ]
)
print(message.content)

With System Prompt

message = client.messages.create(
    model="claude-sonnet-4-20250514",
    max_tokens=1024,
    system="You are a senior software architect. Be concise and technical.",
    messages=[
        {"role": "user", "content": "Review this microservices design."}
    ]
)

Streaming Response

with client.messages.stream(
    model="claude-sonnet-4-20250514",
    max_tokens=1024,
    messages=[{"role": "user", "content": "Write a tutorial on Docker."}]
) as stream:
    for text in stream.text_stream:
        print(text, end="", flush=True)

Best Practices for Claude

Be Explicit About Format

Respond in this exact JSON format:
{
  "summary": "string",
  "confidence": "high|medium|low",
  "sources": ["string"]
}

Use XML Tags for Structure

<document>
[Your document here]
</document>

<instructions>
Summarize the document above in 3 bullet points.
</instructions>

Leverage Long Context

Instead of summarizing first, give Claude the full context:

Here is our entire codebase documentation (15,000 words).
A user asks: "How do I set up authentication?"
Answer their question using specific references to the docs.

Limitations

• Knowledge cutoff (training data date)
• Cannot browse the internet
• Cannot execute code (without tools)
• May be cautious on certain topics
• Costs scale with token usage

Pricing Considerations

Tip: Use Haiku for simple tasks, Sonnet for most development work, Opus for complex analysis.