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).

Quality

73%

Does it follow best practices?

Impact

—

No eval scenarios have been run

Securityby

Advisory

Suggest reviewing before use

Optimize this skill with Tessl

npx tessl skill review --optimize ./.agents/skills/mcp-builder/SKILL.md

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 skill description that clearly identifies its niche (MCP server development), provides explicit 'Use when' guidance with framework-specific triggers, and is distinctive enough to avoid conflicts. The main weakness is that the 'what' portion could be more specific about the concrete actions or guidance it provides beyond the high-level 'creating high-quality MCP servers'.

Suggestions

Add more specific concrete actions to the 'what' portion, e.g., 'defining tools, handling authentication, configuring transport layers, structuring server code' to improve specificity.

Dimension	Reasoning	Score
Specificity	The description names the domain (MCP servers) and a general action ('creating high-quality MCP servers that enable LLMs to interact with external services'), but does not list multiple specific concrete actions like defining tools, handling authentication, setting up transport layers, etc.	2 / 3
Completeness	Clearly answers both 'what' (guide for creating 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, 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', 'Python', 'Node', 'TypeScript', 'external APIs', 'tools'. These cover common variations a user might use when asking about building MCP servers.	3 / 3
Distinctiveness Conflict Risk	MCP server development is a very specific niche. The description clearly targets Model Context Protocol server creation with specific framework mentions (FastMCP, MCP SDK), making it highly unlikely to conflict with other 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 orchestration skill that effectively organizes a complex multi-phase workflow with good progressive disclosure to reference files. Its main weaknesses are moderate verbosity (explaining rationale Claude doesn't need) and insufficient actionability in the main body—most concrete guidance is deferred to reference files, leaving the SKILL.md itself as more of a table of contents than an actionable guide. Adding inline code snippets and explicit validation/error-recovery steps would significantly improve it.

Suggestions

Add at least one concrete, executable code example per language (e.g., a minimal tool registration snippet) directly in the SKILL.md body rather than deferring all code to reference files.

Add explicit validation checkpoints with feedback loops in Phase 3, e.g., 'If build fails: check error output, fix type errors, rebuild. Only proceed to Inspector testing when build succeeds.'

Trim explanatory rationale that Claude already knows—remove sentences like 'Plus AI models are good at generating TypeScript code, benefiting from its broad usage, static typing and good linting tools' and the MCP overview paragraph.

Dimension	Reasoning	Score
Conciseness	The content is moderately efficient but includes unnecessary explanations Claude would already know (e.g., explaining what MCP is, why TypeScript is recommended with rationale about static typing and linting). Some sections like the overview and design philosophy could be significantly tightened. However, it avoids the worst verbosity patterns.	2 / 3
Actionability	The skill provides structural guidance and references to external files but lacks executable code examples in the main body. Instructions like 'Create shared utilities: API client with authentication, Error handling helpers' are directional rather than concrete. The evaluation XML example is a good concrete element, but most implementation guidance is deferred to reference files without inline examples.	2 / 3
Workflow Clarity	The four-phase workflow is clearly sequenced and logically organized. However, validation checkpoints are weak—Phase 3 mentions running build and testing with MCP Inspector but lacks explicit feedback loops (e.g., what to do if build fails, how to verify tools work correctly before proceeding). For a process involving server development with potential destructive operations, the absence of robust validate-fix-retry loops caps this at 2.	2 / 3
Progressive Disclosure	The skill effectively uses a hub-and-spoke model with clear, well-signaled references to language-specific guides, best practices, and evaluation documentation. References are one level deep, use descriptive labels with emoji markers, and are organized by phase. The Reference Files section at the end provides a clean navigation index. Without bundle files to verify, the structure itself is exemplary.	3 / 3
	Total	9 / 12 Passed

Validation

100%

Warnings & errors only

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.

Repository: databricks/devhub
Commit: 49eeda2

Reviewed: 3 days ago

Table of Contents

Discovery Implementation Validation

Is this your skill?

If you maintain this skill, you can claim it as your own. Once claimed, you can manage eval scenarios, bundle related skills, attach documentation or rules, and ensure cross-agent compatibility.