Apideck CLI: A Low-Context Alternative to MCP for AI Agents

MCP's Context Window Problem

The article describes a specific scenario: connecting GitHub, Slack, and Sentry via MCP servers (about 40 tools total) consumes 55,000+ tokens before the agent processes a single user message. That's over a quarter of Claude's 200k limit. Each MCP tool definition costs 550–1,400 tokens for its name, description, JSON schema, field descriptions, enums, and system instructions.

One team reported three MCP servers consuming 143,000 of 200,000 tokens (72% of the context window), leaving only 57,000 tokens for actual conversation, retrieved documents, reasoning, and response.

David Zhang (@dzhng), building Duet, described removing MCP integrations entirely due to a "trilemma": load everything up front and lose working memory, limit integrations so the agent can only talk to a few services, or build dynamic tool loading which adds latency and middleware complexity.

Benchmark Results

A benchmark by Scalekit ran 75 head-to-head comparisons (same model: Claude Sonnet 4, same tasks, same prompts) and found:

• MCP costs 4 to 32× more tokens than CLI for identical operations
• Checking a repo's language consumed 1,365 tokens via CLI vs 44,026 via MCP
• The overhead is almost entirely schema: 43 tool definitions injected into every conversation, of which the agent uses one or two

Apideck CLI Approach

The Apideck CLI uses an ~80-token agent prompt that replaces tens of thousands of tokens of schema. It features progressive disclosure via --help and structural safety baked into the binary. Any agent that can run shell commands can use it without requiring protocol support.

Industry Responses to Context Bloat

The article identifies three industry approaches:

• MCP with compression tricks: Compress schemas, use tool search to load definitions on demand, or build middleware that slices OpenAPI specs into smaller chunks. This works for small, well-defined interactions but adds infrastructure needs (tool registry, search logic, caching, routing).
• CLI-first interfaces: The approach taken by Apideck CLI.
• Agent-native protocols: Mentioned but not detailed in the provided source text.