mcp-builder
Guide for creating high-quality MCP (Model Context Protocol) servers that enable LLMs to interact with external services through well-designed tools. Use when building MCP servers to integrate external APIs or services, whether in Python (FastMCP) or Node/TypeScript (MCP SDK).
Install with Tessl CLI
npx tessl i github:boisenoise/skills-collections --skill mcp-builder93
Does it follow best practices?
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npx tessl skill review --optimize ./path/to/skillEvaluation — 94%
↑ 2.23xAgent success when using this skill
Validation for skill structure
Discovery
89%Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.
This is a solid description with excellent trigger terms and completeness. The explicit 'Use when...' clause and specific technology mentions (FastMCP, MCP SDK) make it highly discoverable. The main weakness is that the capabilities could be more concrete—listing specific actions like schema definition, tool implementation, or resource handling would strengthen it.
Suggestions
Add specific concrete actions like 'define tool schemas', 'implement resource handlers', 'configure authentication' to improve specificity
| Dimension | Reasoning | Score |
|---|---|---|
Specificity | Names the domain (MCP servers) and general purpose (enable LLMs to interact with external services), but lacks specific concrete actions like 'define tool schemas', 'handle authentication', or 'implement resource endpoints'. | 2 / 3 |
Completeness | Clearly answers both what ('creating high-quality MCP servers that enable LLMs to interact with external services through well-designed tools') and when ('Use when building MCP servers to integrate external APIs or services') with explicit language triggers. | 3 / 3 |
Trigger Term Quality | Includes strong natural keywords users would say: 'MCP', 'Model Context Protocol', 'MCP servers', 'FastMCP', 'MCP SDK', 'Python', 'Node', 'TypeScript', 'external APIs', 'services', 'tools'. | 3 / 3 |
Distinctiveness Conflict Risk | MCP servers are a very specific niche with distinct terminology (FastMCP, MCP SDK, Model Context Protocol). Unlikely to conflict with general API or server-building skills due to the specialized domain. | 3 / 3 |
Total | 11 / 12 Passed |
Implementation
70%Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.
This skill provides a well-structured, comprehensive workflow for MCP server development with excellent progressive disclosure and clear phase-based organization. However, it could be more concise by trimming explanatory content Claude already knows, and more actionable by including at least one concrete code example inline rather than deferring all examples to reference files.
Suggestions
Add one minimal executable code example inline (e.g., a basic tool registration in TypeScript) to demonstrate the pattern before pointing to reference files
Trim explanatory content like 'The quality of an MCP server is measured by...' and the detailed TypeScript justification - Claude understands these concepts
Consider moving the 'Annotations' bullet list to a reference file since it's detailed reference material rather than workflow guidance
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The content is reasonably efficient but includes some unnecessary explanation (e.g., explaining why TypeScript is recommended with multiple justifications, general statements about MCP quality). Some sections could be tightened while preserving clarity. | 2 / 3 |
Actionability | Provides good structural guidance and references to external resources, but lacks concrete executable code examples within the main skill file itself. Most actionable content is deferred to reference files rather than shown inline. | 2 / 3 |
Workflow Clarity | Clear four-phase workflow with explicit sequencing (Research → Implementation → Review/Test → Evaluations). Each phase has numbered sub-steps, and Phase 3 includes validation checkpoints (build verification, testing with MCP Inspector). | 3 / 3 |
Progressive Disclosure | Excellent structure with clear overview and well-signaled one-level-deep references to language-specific guides, best practices, and evaluation documentation. Reference files section provides organized navigation to all supporting materials. | 3 / 3 |
Total | 10 / 12 Passed |
Validation
100%Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.
Validation — 11 / 11 Passed
Validation for skill structure
No warnings or errors.
- Reviewed
Table of Contents
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