claude-code-ultimate-guide/cowork/guide/02-capabilities.md

Cowork Capabilities

Reading time: ~8 minutes

Purpose: Understand exactly what Cowork can and cannot do

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Capability Matrix

File Operations

Operation	Can Do	Notes
Read files	✅ Yes	Any format in granted folder
Create files	✅ Yes	Any text-based format
Move files	✅ Yes	Within granted folders
Copy files	✅ Yes	Within granted folders
Rename files	✅ Yes	Bulk renaming supported
Delete files	✅ Yes	⚠️ Permanent, no trash
Create folders	✅ Yes	Nested structures supported
Extract archives	❌ No	Cannot run unzip/tar
Compress files	❌ No	Cannot create archives

Document Generation

Format	Can Create	Features
Plain text (.txt)	✅ Yes	Any content
Markdown (.md)	✅ Yes	Full formatting
Word (.docx)	✅ Yes	Headers, tables, formatting
Excel (.xlsx)	✅ Yes	Formulas, multiple sheets, formatting
PowerPoint (.pptx)	✅ Yes	Slides, basic formatting
PDF	✅ Yes	Generated from content
HTML	✅ Yes	Full HTML/CSS
CSV	✅ Yes	Data export
JSON	✅ Yes	Structured data

Input Processing

Input Type	Can Process	Notes
Text files	✅ Yes	Any encoding
Office docs	✅ Yes	Word, Excel, PowerPoint
PDFs	✅ Yes	Text extraction
Images	✅ Yes	OCR for text extraction
Screenshots	✅ Yes	Receipt/document scanning
Markdown	✅ Yes	Full parsing
CSV/JSON	✅ Yes	Structured data parsing
Audio	❌ No	Cannot process
Video	❌ No	Cannot process
Encrypted files	❌ No	Cannot decrypt

Web Capabilities (via Chrome)

Action	Can Do	Notes
Search web	✅ Yes	Via Chrome integration
Read pages	✅ Yes	Extract content
Save content	✅ Yes	To local files
Fill forms	⚠️ Limited	Requires explicit approval
Make purchases	❌ No	Security restriction
Login to sites	❌ No	Security restriction
API calls	❌ No	No direct network access

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Detailed Capabilities

1. File Organization

Cowork excels at organizing large numbers of files:

INPUT:  500 files in Downloads folder
OUTPUT: Organized structure by type/date/project

What Cowork Does:

• Analyzes file names, types, content
• Proposes organizational schema
• Creates folder structure
• Moves files (with your approval)
• Generates organization report

Limitations:

• Cannot access file metadata (creation date, etc.) reliably
• Cannot read file content for some binary formats
• Relies on file names/extensions for categorization

2. Document Synthesis

Combine multiple sources into structured outputs:

INPUT:  15 meeting notes, 3 reports, 5 emails (as text files)
OUTPUT: Executive summary with key decisions and action items

What Cowork Does:

• Reads all source documents
• Identifies key themes and information
• Structures into requested format
• Generates polished output document

Limitations:

• Context window limits (~200K tokens)
• Cannot access original email/calendar systems
• Synthesis quality depends on source clarity

3. Data Extraction

Extract structured data from unstructured sources:

INPUT:  20 receipt images (photos, screenshots)
OUTPUT: Excel spreadsheet with Date, Vendor, Amount, Category

What Cowork Does:

• OCR on images
• Identifies relevant fields
• Normalizes data format
• Creates Excel with formulas

Limitations:

• Field extraction: ~97% accuracy (vendor, date, totals)
• Line-item extraction: ~63% accuracy (table rows) — verify manually
• Handwritten text is challenging
• Some receipt formats may not parse correctly
• Budget 30-50% of "saved" time for error correction

⚠️ No independent benchmarks exist for AI file organization tools. Productivity claims are vendor marketing, not peer-reviewed research. Set realistic expectations.

4. Report Generation

Create formatted reports from raw data:

INPUT:  CSV with sales data
OUTPUT: Formatted report with charts and analysis

What Cowork Does:

• Analyzes data patterns
• Creates summary statistics
• Generates visual representations
• Formats for specified output

Limitations:

• Chart capabilities limited in Excel output
• Complex visualizations need manual refinement
• Statistical analysis is basic

5. Research Compilation

Gather and organize research from multiple sources:

INPUT:  Topic: "Remote work productivity tools"
OUTPUT: Research document with comparison matrix

What Cowork Does:

• Uses Chrome for web research
• Extracts relevant information
• Organizes into structured format
• Cites sources

Limitations:

• Cannot access paywalled content
• Web research is slower than direct API
• Quality depends on available public information

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Excel Capabilities (Detailed)

Since Excel output is a major Cowork strength:

Supported Features

Feature	Supported	Example
Basic formulas	✅ Yes	=SUM(A1:A10)
Conditional formulas	✅ Yes	=IF(A1>100, "High", "Low")
VLOOKUP/HLOOKUP	✅ Yes	Cross-reference sheets
Multiple sheets	✅ Yes	Summary + detail sheets
Cell formatting	✅ Yes	Bold, colors, borders
Number formatting	✅ Yes	Currency, percentages
Data validation	⚠️ Limited	Basic dropdown lists
Pivot tables	❌ No	Must create manually
Macros/VBA	❌ No	Security restriction
Charts	⚠️ Limited	Basic chart types

Regional Considerations

Excel formula syntax varies by region:

• US/UK: =SUM(A1,A2) (comma separator)
• EU: =SUM(A1;A2) (semicolon separator)

Tip: Specify your regional setting in prompts:

Create an Excel file using European formula syntax (semicolon separators)

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Context Window Usage

Cowork shares Claude's ~200K token context limit, but effective capacity is ~165K.

Why 165K, Not 200K?

System overhead consumes tokens before your task starts:

• Tool definitions: ~10K tokens
• Safety instructions: ~10K tokens
• Execution logs: ~5-15K tokens (varies)

Effective limit: ~165-175K usable tokens

Practical Limits

Content Type	Approximate Capacity
Plain text pages	100-400 pages
Documents	40-80 typical docs
Spreadsheet rows	8,000-40,000 rows
Images (OCR)	40-80 images

When You Hit Limits

Error message:

Context limit reached

Symptoms:

• Cowork stops mid-task (often around 165K, not 200K)
• Results are incomplete
• Silent failure without clear message

Solutions:

• Break work into batches of 10-20 files
• Process files in groups
• Save intermediate results to checkpoint files
• Start fresh conversation for new tasks

Token Budget by Task Type

Task	Tokens	Pro Sessions
Simple Q&A	5K-10K	Many
File inventory	20K-30K	6-8
Small file org (10-20 files)	30K-50K	3-5
Large file org (50+ files)	80K-150K	1-2
OCR batch (10+ images)	60K-100K	2-3

Agentic overhead: Plan→Execute→Check cycles add 15-30% tokens.

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What Cowork CANNOT Do

Code Execution

❌ Cannot run: Python, JavaScript, shell scripts
❌ Cannot execute: Installed applications
❌ Cannot use: Command-line tools

Workaround: Use Claude Code for code execution tasks.

Network Operations

❌ Cannot make: API calls, HTTP requests
❌ Cannot access: Remote databases
❌ Cannot sync: Cloud storage directly

Workaround: Download cloud files locally first, or use Chrome for web access.

System Operations

❌ Cannot change: System settings
❌ Cannot install: Software
❌ Cannot access: Other applications' data

Workaround: These operations must be done manually.

Security-Sensitive Operations

❌ Cannot handle: Passwords, credentials
❌ Cannot process: Encrypted files
❌ Cannot access: Protected system folders

Workaround: Keep sensitive data out of Cowork workspace.

Environment Constraints

❌ Cannot work: With VPN active (VM routing conflict)
❌ Cannot run: On Windows or Linux (macOS only)
❌ Cannot operate: In background (requires app foreground)
❌ Cannot persist: Sessions across app restarts

VPN Issue: Cowork's VM conflicts with VPN network routing. This is the #1 reported issue. Solution: Disconnect VPN before using Cowork. See Troubleshooting for details.

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Capability Decision Tree

Need to do something with files?
├─ Yes → Is it within your granted folder?
│        ├─ Yes → Can Cowork read the file type?
│        │        ├─ Yes → Cowork can help ✅
│        │        └─ No (audio/video/encrypted) → Manual process needed
│        └─ No → Grant access or move files first
│
└─ No → What do you need?
         ├─ Execute code → Use Claude Code
         ├─ API integration → Manual or Claude Code
         ├─ System changes → Manual operation
         └─ Web research → Cowork + Chrome ✅

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Best Practices for Capabilities

Maximize Success

1. Match task to capability — Check matrix before starting
2. Prepare inputs — Ensure files are in readable formats
3. Specify formats — Be explicit about output requirements
4. Test small first — Verify with few files before batch

When to Choose Alternatives

If You Need	Use Instead
Code execution	Claude Code
API integration	Claude Code + scripts
Cloud file sync	Native cloud apps
Audio/video	Specialized tools
Real-time data	Manual process

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