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mcp-builder-ms

Use this skill when building MCP servers to integrate external APIs or services, whether in Python (FastMCP) or Node/TypeScript (MCP SDK).

44

Quality

45%

Does it follow best practices?

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SecuritybySnyk

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tessl review fix ./skills/mcp-builder-ms/SKILL.md
SKILL.md
Quality
Evals
Security

Quality

Content

35%Scale 1-5

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 reasonable high-level framework for MCP server development with a clear four-phase workflow, but it suffers from significant verbosity and lack of actionable, executable content. The document is heavy on organizational structure and reference links but light on concrete code examples, relying almost entirely on external guides (none provided in the bundle) for actual implementation details. The redundancy between inline references and the Reference Files section inflates token usage without adding value.

Suggestions

Add at least one complete, minimal working example of an MCP server (e.g., a 20-line TypeScript or Python server with one tool) to make the guide immediately actionable rather than purely referential.

Remove the Reference Files section at the bottom, as it duplicates links already provided inline throughout the phases—or consolidate all references to one location only.

Trim the Microsoft MCP ecosystem section significantly or move it to a separate reference file, as it's tangential to the core task of building custom MCP servers.

Add explicit validation checkpoints between phases (e.g., 'Before moving to Phase 2, verify: API endpoints identified, auth method confirmed, tool list finalized') to improve workflow clarity.

DimensionReasoningScore

Conciseness

The skill is noticeably verbose with significant redundancy. The Microsoft MCP ecosystem section, while potentially useful, adds substantial length. The Reference Files section at the end largely duplicates links and descriptions already provided inline throughout the phases. Multiple tables explain things Claude would already know (e.g., what stdio vs HTTP transports are). The document could be cut by 40%+ without losing actionable content.

2 / 5

Actionability

Despite being a development guide, the skill contains almost no executable code examples. Instructions are high-level and abstract ('Create shared utilities: API client with authentication, Error handling helpers'). The only concrete commands are build/test commands like `npm run build`. Tool implementation guidance is a bullet-point checklist rather than concrete, copy-paste-ready code. Most actionable content is deferred to external references that aren't provided in the bundle.

2 / 5

Workflow Clarity

The four-phase workflow (Research, Implementation, Review, Evaluation) provides a clear sequence, and the sub-steps within each phase are logically ordered. However, there are no validation checkpoints or feedback loops between phases. Phase 3 (Review and Test) mentions testing but lacks explicit validation gates or error recovery steps. For a process that involves building servers that interact with external services, the absence of 'validate before proceeding' patterns is a gap.

3 / 5

Progressive Disclosure

The skill references multiple external guides (Python Guide, TypeScript Guide, Microsoft MCP Patterns, Evaluation Guide, Best Practices) with emoji markers and brief descriptions, which is good structure. However, no bundle files are provided, so all these references are unverifiable. The Reference Files section at the bottom duplicates the inline references, creating redundancy rather than clean navigation. The inline content itself is somewhat monolithic with tables and lists that could be in separate files.

3 / 5

Total

10

/

20

Passed

Description

56%Scale 1-5

Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.

The description clearly identifies when to use the skill (building MCP servers) and names specific frameworks, giving it reasonable trigger term coverage and distinctiveness. However, it lacks concrete actions describing what the skill actually teaches or enables—there are no specific capabilities listed like scaffolding projects, defining tools/resources, handling authentication, or configuring transports. The 'what' and 'when' are essentially collapsed into the same clause.

Suggestions

Add concrete actions describing what the skill covers, e.g., 'Scaffolds MCP server projects, defines tools and resources, configures transports, and handles authentication for external API integration.'

Expand trigger terms to include synonyms and related phrases like 'Model Context Protocol', 'MCP tool', 'MCP resource', 'MCP integration', or 'connect Claude to external services'.

Separate the 'what' from the 'when' more clearly, e.g., list capabilities first, then provide a 'Use when...' clause with specific trigger scenarios.

DimensionReasoningScore

Specificity

Names the domain (MCP servers, external APIs/services) and mentions two technology stacks (Python/FastMCP, Node/TypeScript/MCP SDK), but describes no concrete actions—no mention of what building an MCP server actually entails (e.g., defining tools, handling requests, configuring transports).

2 / 5

Completeness

Has an explicit 'when' clause ('Use this skill when building MCP servers to integrate external APIs or services'), but the 'what' is only weakly implied—it says to use it when building MCP servers but never describes what the skill actually teaches or does (e.g., scaffolding, defining tools, connecting to APIs). The 'what' is essentially just restated as the 'when'.

3 / 5

Trigger Term Quality

Includes several natural keywords a user might say: 'MCP servers', 'external APIs', 'Python', 'FastMCP', 'Node', 'TypeScript', 'MCP SDK'. Missing some variations like 'Model Context Protocol', 'MCP tool', or 'MCP integration' that users might also use.

4 / 5

Distinctiveness Conflict Risk

MCP server development is a fairly specific niche, and the mention of FastMCP and MCP SDK narrows it further. Minor overlap risk with general API integration or Python/TypeScript development skills, but the MCP focus is distinctive enough.

4 / 5

Total

13

/

20

Passed

Validation

90%

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation10 / 11 Passed

Validation for skill structure

CriteriaDescriptionResult

frontmatter_unknown_keys

Unknown frontmatter key(s) found; consider removing or moving to metadata

Warning

Total

10

/

11

Passed

Repository
administrakt0r/AI-Agents-Safe-Coding-Skills
Reviewed

Table of Contents

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