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Architectural Comparison
9.1🔒The Fundamental DifferenceMCP connects the agent to external capabilities (tools, data, APIs). Skills teach the agent how to use those capabilities for specific…
9.2🔒How Each Approach WorksLoaded per API call: 15-25 tool schemas (~5,000-12,500 tokens), an accessibility tree per page (~2,000-10,000 tokens) streamed inline on…
9.3🔒Detailed ComparisonNote the framing. The mechanism can produce much larger per-step ratios on paper -- 20x, 30x, more. The honest, measured number for full…
9.4🔒The Decision Matrix1. Your agent has filesystem access -- Claude Code, Cursor, CI runners. The disk is the context-overflow valve; no disk, no trick. 2. Your…
9.5🔒Microsoft's Own AssessmentEarlier editions argued the token math from estimates. As of 2026, you can simply cite the vendor: Microsoft recommends the Playwright CLI…
9.6🔒Key Takeaways- Skills and MCP are complementary layers: MCP provides capabilities, skills teach efficient use of them. - The architectural pivot is…
9.7🔒Q&ASelf-Assessment Quiz1. In one sentence each: what does MCP provide to an agent, and what does a skill provide? 2. What is the single architectural difference…
9.8🔒Exercises[Beginner] Exercise 9.1: Without looking back, draw the two architecture diagrams (MCP server and CLI skill) from memory, labeling what is…
9.9🔒Career Translation- Conducted a comparative architectural analysis of skill (CLI) and MCP (server) approaches for browser automation, evaluating token…
9.10🔒Q&AInterview Depth CheckPrompt: An architect asks: "MCP gives the agent rich semantic understanding of the page via accessibility trees. Doesn't the CLI approach…