validate_css_file

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations, but description details validations performed (Shadow DOM, ::part(), tokens, contrast, etc.) and mentions antiPatterns and fix objects. Does not mention side effects, but likely read-only.

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?

Concise, front-loaded, every sentence adds value. Well-structured, no waste.

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?

Complex tool with multiple validation types and grouped results. Description covers return format (issues grouped by component, fix objects) and key validations. No output schema, so description compensates well.

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 coverage 100%, baseline 3. Description adds minimal new meaning; libraryId and cssText descriptions are already in schema.

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?

Description clearly states it validates a CSS file for multiple web components, auto-detects tags, and runs per-component and global validation. Distinguishes from siblings which are more specific.

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?

Explicitly says to use when reviewing a CSS file with multiple components, implying not for single components or specific checks. Does not list alternatives but context of sibling tools provides that.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.