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mcp-builder

Create MCP (Model Context Protocol) servers that enable LLMs to interact with external services through well-designed tools. The quality of an MCP server is measured by how well it enables LLMs to accomplish real-world tasks.

45

Quality

48%

Does it follow best practices?

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SecuritybySnyk

Passed

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tessl review fix ./plugins/antigravity-bundle-agent-architect/skills/mcp-builder/SKILL.md

The canonical home for this skill is mcp-builder in administrakt0r/AI-Agents-Safe-Coding-Skills

SKILL.md
Quality
Evals
Security

Quality

Content

60%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 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 that the SKILL.md itself is light on concrete, executable guidance—deferring most actionable content to reference files—and includes some unnecessary explanatory text that could be trimmed. The workflow is clear but could benefit from more explicit validation checkpoints and error recovery patterns.

Suggestions

Add concrete, executable code examples directly in the SKILL.md for at least one common case (e.g., a minimal TypeScript MCP server skeleton with one tool) rather than deferring all code to reference files.

Trim explanatory text that Claude already knows—e.g., remove the parenthetical explaining why TypeScript is recommended and the re-statement of the overview in the body.

Add explicit validation checkpoints with error recovery in Phase 2/3, such as 'If build fails with type errors, check Zod schema definitions match API response shapes' to strengthen the feedback loop.

DimensionReasoningScore

Conciseness

The skill contains some unnecessary explanation (e.g., explaining why TypeScript is recommended with multiple justifications, restating the overview description, explaining what MCP is). The phased structure adds organizational overhead. However, it's not egregiously verbose—most sections contain useful guidance rather than pure padding.

3 / 5

Actionability

The skill provides a structured workflow and references to implementation guides, but the SKILL.md itself contains mostly high-level guidance rather than executable code or commands. Concrete examples are sparse—the only code shown is the evaluation XML format. Most actionable content is deferred to reference files (which aren't provided), leaving the main file as more of an outline than executable guidance.

3 / 5

Workflow Clarity

The four-phase workflow is clearly sequenced with logical progression from research through evaluation. Phase 3 includes build verification steps. However, validation checkpoints are somewhat implicit—there's no explicit 'if X fails, do Y' feedback loop in the main workflow. The testing section mentions tools but doesn't define clear pass/fail criteria or error recovery steps.

4 / 5

Progressive Disclosure

The skill effectively uses a hub-and-spoke model with clear references to language-specific guides, best practices, evaluation guide, and external SDK documentation. References are well-signaled with emoji markers and descriptive summaries. The Reference Files section at the end provides a good navigation index. Minor issue: some references are repeated (e.g., the TypeScript and Python guides appear in multiple phases), and without bundle files to verify, we can't confirm all paths resolve correctly.

4 / 5

Total

14

/

20

Passed

Description

36%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 identifies the MCP server domain but remains too abstract, lacking concrete actions and explicit trigger guidance. The second sentence about quality measurement adds no selection value and wastes space that could specify when to use this skill. It needs concrete capabilities, natural trigger terms, and a clear 'Use when...' clause.

Suggestions

Add a 'Use when...' clause with trigger phrases like 'when the user asks to build or create an MCP server, implement MCP tools, or connect LLMs to external APIs'.

Replace the vague quality statement with concrete actions such as 'define tool schemas, implement request/response handlers, set up authentication, configure transport layers'.

Include natural synonyms and related terms users might say, such as 'MCP tool', 'MCP integration', 'Claude tool use', 'external API', or specific framework names.

DimensionReasoningScore

Specificity

Names the domain (MCP servers) but the actions are generic — 'create MCP servers' and 'interact with external services through well-designed tools' are vague. No concrete actions like 'define tool schemas', 'handle authentication', or 'implement request handlers' are mentioned.

2 / 5

Completeness

Has a vague 'what' (create MCP servers for LLM-external service interaction) but no 'when' clause at all. The second sentence describes quality criteria rather than trigger conditions. Missing explicit 'Use when...' guidance caps this low.

2 / 5

Trigger Term Quality

Includes 'MCP', 'Model Context Protocol', 'servers', 'tools', and 'LLMs' which are relevant keywords. However, it misses natural user phrases like 'build an MCP server', 'MCP tool', 'external API integration', or file/framework-specific terms users might mention.

3 / 5

Distinctiveness Conflict Risk

MCP is a fairly specific domain which helps, but 'interact with external services' and 'well-designed tools' are broad enough to overlap with general API integration or tool-building skills. The lack of concrete boundaries increases conflict risk.

3 / 5

Total

10

/

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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