Claude Code Decision Framework / 2026
Skills vs MCP vs CLI
When to use what
The definitive decision framework for Claude Code in 2026. Pick the right tool every time — no guessing, no wasted tokens.
.claude/skills/
markdown + scripts
mcp.json
external protocol
$ terminal
standard unix
Side-by-side comparison
Green bars mark the winner for each dimension
What it is
Markdown instructions + scripts in
.claude/skills/External servers exposing tools via protocol
Standard command-line programs
Token cost
Low — loaded once into context
High — schema sent every call
Lowest — one bash command
Best for
Complex workflows, multi-step processes, domain knowledge
External service integration (APIs with auth)
Simple operations, data processing
Setup
Drop folder in
.claude/skills/Configure
mcp.json, run serverbrew install, doneTrust level
Lowest — user-defined, full control
Medium — plugin model
Highest — built-in bash
Composability
Chains via Claude reasoning
Isolated per server
Unix pipes — any with any
When to pick
Need Claude to follow a process
Need real-time API connection
Need fast, cheap tool access
Example
infographic-maker, cold-danceAttio CRM, Apollo enrichmentgh, jq, ffmpegDecision tree
Three questions. One answer.
Need domain knowledge or multi-step process?
Skill
Need live API connection with auth?
MCP Server
Need fast, cheap tool access?
CLI Tool
When to pick each
Practical signals that guide your choice
Skills
- You want Claude to follow a defined process
- Workflow spans multiple steps or files
- You need domain-specific knowledge injected
- Fast iteration — just edit a markdown file
- No server infrastructure required
- Example:
infographic-maker, deploy workflows
MCP Servers
- Real-time API calls with OAuth or secrets
- Structured tool schema matters to Claude
- Third-party service integration (CRM, billing)
- Multiple agents share the same server
- Protocol-level reliability needed
- Example:
Attio CRM,Apollo enrichment
CLI Tools
- Single-command data operation
- Unix piping or stream processing
- Token budget is tight — bash is cheapest
- Already installed globally on the machine
- No auth or state needed
- Example:
gh,jq,ffmpeg
Skills are maybe a bigger deal than MCP.
Simon Willison — simonwillison.net / Confluent 132K video