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create-mcp-server

Build, iterate, and evaluate Model Context Protocol (MCP) servers that expose external services as tools an LLM can call. Use when asked to "build an MCP server", "create an MCP tool", "wrap this API as MCP", "expose X to Claude", or when extending GSD with custom tool integrations. Covers research, schema/tool design, error handling, pagination, testing via MCP Inspector, and producing a 10-question eval set that proves the server actually enables real work.

68

Quality

81%

Does it follow best practices?

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SecuritybySnyk

Passed

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SKILL.md
Quality
Evals
Security

Quality

Content

62%

Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.

A well-structured, actionable authoring guide with a clear workflow and explicit validation loops. Its main weaknesses are a lack of executable code examples and a monolithic layout with no progressive disclosure to reference files.

Suggestions

Add at least one minimal but executable TypeScript tool definition (name, description, JSON Schema, handler) so the guidance is copy-paste ready rather than prose-only.

Tighten <core_principle> and <context>: drop the GSD-2 internal file-path enumeration and rhetorical flourishes, keeping only the load-bearing design rules.

Move the eval XML format and project skeleton into reference files under references/ (e.g. EVAL_TEMPLATE.md, SKELETON.md) and link to them from the body to enable progressive disclosure.

DimensionReasoningScore

Conciseness

The body is mostly efficient and does not explain MCP basics, but <core_principle> and <context> carry preachy or boilerplate phrasing ('write it like documentation for a stranger under time pressure', GSD-2 file-path listing) that could be tightened. It is not 3 because some tokens do not purely earn their place, and not 1 because it avoids concept padding.

2 / 3

Actionability

Provides concrete guidance (verb-noun naming, JSON Schema field requirements, error/pagination phrasings, an eval XML template, a skeleton tree), but for a code-producing skill it offers no executable TypeScript example — only a file tree and prose. It is not 3 because the code is not copy-paste executable, and not 1 because the instructions are specific and directive.

2 / 3

Workflow Clarity

A clear six-step sequence with explicit validation checkpoints: Step 4 runs the Inspector and checks error paths, Step 5 runs evals and iterates ('If the model can't complete them, the server — not the model — needs work'), and a success_criteria checklist closes the loop.

3 / 3

Progressive Disclosure

The body is organized into clear tagged sections (objective, context, core_principle, process, anti_patterns, success_criteria) with no deep nesting, but it is a single monolithic file over 50 lines with no bundle references and inline content (eval format, skeleton) that could be split out. It is not 3 because there are no well-signaled one-level-deep references, and not 1 because organization is clean rather than a wall of text.

2 / 3

Total

9

/

12

Passed

Description

100%

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

A strong, specific description with explicit 'Use when' triggers and natural user phrasings, written in third person. It clearly communicates both capability and invocation conditions with no vagueness or over-claims.

DimensionReasoningScore

Specificity

Names multiple concrete actions — 'Build, iterate, and evaluate MCP servers' plus a covers list of 'research, schema/tool design, error handling, pagination, testing via MCP Inspector, and producing a 10-question eval set' — matching the 'lists multiple specific concrete actions' anchor.

3 / 3

Completeness

Explicitly answers both 'what' (build/iterate/evaluate servers plus the covers list) and 'when' (an explicit 'Use when...' clause), satisfying the both-what-and-when anchor.

3 / 3

Trigger Term Quality

Includes natural phrasings a user would actually say — 'build an MCP server', 'create an MCP tool', 'wrap this API as MCP', 'expose X to Claude' — giving good coverage of common variations, not jargon.

3 / 3

Distinctiveness Conflict Risk

Occupies a clear MCP-server-authoring niche with distinct, specific triggers; unlikely to fire for unrelated skills. It is not the level below because it is not generic and does not overlap with broad document/file skills.

3 / 3

Total

12

/

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.

Validation16 / 16 Passed

Validation for skill structure

No warnings or errors.

Repository
gsd-build/gsd-2
Reviewed

Table of Contents

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