Parse and validate only the YAML frontmatter of a Claude Skill. Returns parsed fields and any rule violations. Use during iterative authoring.
| Name | Required | Description | Default |
|---|---|---|---|
| yaml | Yes | Raw YAML content without --- delimiters (just key: value lines) |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the burden. It discloses the read-only nature by saying 'parse and validate' and explicitly mentions return values ('parsed fields and any rule violations'). It could be more explicit about no side effects, but the described actions are inherently non-destructive and output is clarified.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Three short sentences front-load the purpose, then return behavior, then usage guidance. There is no redundant wording or filler, making it tightly packed and effective.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
The tool is simple (one param, no output schema, no annotations), and the description covers purpose, output, and when to use it. It lacks detail on specific violation categories, but for a linter of this scope, the return summary is adequate and complete enough for an agent to invoke correctly.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 100%, so the parameter is well-documented. The description adds domain context by specifying 'Claude Skill' frontmatter and clarifying scope ('only'), which enriches the schema beyond raw syntax. It does not add format details beyond the schema, but the additional context earns above baseline.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states it 'Parse[s] and validate[s] only the YAML frontmatter of a Claude Skill,' using a specific verb and resource. It also distinguishes itself from siblings like validate_skill by scoping to frontmatter only.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description says 'Use during iterative authoring,' providing a clear usage context. However, it does not explicitly name alternatives or exclusions; the word 'only' implies a narrower scope than full-skill validation but a direct sibling reference would strengthen it.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
Most tools are distinct, but score_skill and validate_skill both run full validation and return score/gate, creating overlap. Descriptions help by distinguishing minimal CI/CD payload from detailed structured errors, but the boundaries are not instantly clear.
All tool names follow a consistent verb_noun snake_case pattern: lint_frontmatter, scan_security, score_skill, validate_skill. This is highly predictable and easy to reason about.
Four tools is an appropriate size for a validation server, covering specific checks and a full validation without bloat or thinness.
The server covers frontmatter linting, security scanning, scoring, and full validation including tool collision checks. No obvious missing operations for the stated purpose of validating Claude Skills.