jbvc/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).
83
83%
Does it follow best practices?
Impact
Pending
No eval scenarios have been run
Advisory
Suggest reviewing before use
Quality
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 that clearly identifies its niche (MCP server development) and provides explicit 'Use when' guidance with framework-specific triggers. Its main weakness is that it could be more specific about the concrete actions it covers (e.g., defining tools, configuring transports, handling authentication) rather than staying at the high-level 'creating servers' framing.
Suggestions
Add specific concrete actions the skill covers, e.g., 'defining tools and resources, configuring transports, structuring server code, handling authentication' to improve specificity.
| Dimension | Reasoning | Score |
|---|---|---|
Specificity | Names the domain (MCP servers) and a general action ('creating high-quality MCP servers that enable LLMs to interact with external services through well-designed tools'), but doesn't list multiple specific concrete actions like defining tools, handling authentication, setting up transport layers, etc. | 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' (explicitly states 'Use when building MCP servers to integrate external APIs or services, whether in Python (FastMCP) or Node/TypeScript (MCP SDK)'). | 3 / 3 |
Trigger Term Quality | Includes strong natural keywords users would say: 'MCP', 'Model Context Protocol', 'MCP servers', 'FastMCP', 'MCP SDK', 'external APIs', 'Python', 'Node', 'TypeScript', 'tools'. These cover the main variations a user building MCP servers would naturally mention. | 3 / 3 |
Distinctiveness Conflict Risk | MCP server development is a very specific niche with distinct trigger terms (MCP, Model Context Protocol, FastMCP, MCP SDK). Unlikely to conflict with general coding skills or other integration-related skills. | 3 / 3 |
Total | 11 / 12 Passed |
Implementation
57%Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.
This is a well-structured skill that effectively organizes a complex multi-phase workflow with good progressive disclosure to reference materials. Its main weaknesses are the lack of executable code examples in the body (deferring nearly all concrete implementation to reference files) and some verbosity in explaining rationale that Claude doesn't need. The workflow would benefit from explicit validation/error-recovery checkpoints in the implementation phases.
Suggestions
Add at least one minimal executable code example in Phase 2 (e.g., a basic TypeScript tool registration with Zod schema) so the main file has concrete, copy-paste-ready guidance rather than deferring everything to reference files.
Add explicit validation checkpoints and error recovery steps in Phase 2 (e.g., 'After implementing each tool, test it with MCP Inspector before proceeding to the next tool').
Remove the Reference Files section at the bottom, which largely duplicates links and descriptions already provided inline during each phase, saving ~30 lines of redundant content.
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The skill contains some unnecessary explanation (e.g., explaining why TypeScript is recommended with multiple justifications, restating concepts like 'quality of an MCP server is measured by how well it enables LLMs'). The reference files section largely duplicates information already presented in the phases. However, it's not egregiously verbose—most content serves a purpose. | 2 / 3 |
Actionability | The skill provides a structured process with specific URLs, tool names, and framework references, but lacks executable code examples in the main body. Implementation guidance is mostly descriptive ('Create shared utilities', 'Use Zod or Pydantic') rather than showing concrete, copy-paste-ready code. The real actionable content is deferred to reference files. | 2 / 3 |
Workflow Clarity | The four-phase workflow is clearly sequenced and logically organized. However, validation checkpoints are weak—Phase 3 mentions 'run build' and 'verify syntax' but lacks explicit feedback loops (e.g., what to do if build fails, how to iterate). The evaluation phase has good structure but the implementation phases lack error recovery steps. | 2 / 3 |
Progressive Disclosure | Excellent use of progressive disclosure with a clear overview in the main file and well-signaled one-level-deep references to language-specific guides, best practices, evaluation guide, and SDK documentation. References are clearly labeled with emoji icons and brief descriptions of what each contains. | 3 / 3 |
Total | 9 / 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