Run PageSpeed Insights and Core Web Vitals analysis on any URL to identify performance issues and optimize page speed.
Run PageSpeed Insights & Core Web Vitals performance analysis for a page.
| Name | Required | Description | Default |
|---|---|---|---|
| url | Yes | The URL to analyze | |
| cwvOnly | No | Return Core Web Vitals metrics only | |
| category | No | Lighthouse categories | |
| strategy | No | Device strategy |
Changes observed during successful MCP inspections.
v2.0.2Input schema / properties / categoryAdded value: +{
+ "description": "Lighthouse categories",
+ "items": {
+ "type": "string"
+ },
+ "type": "array"
+}Input schema / properties / cwvOnlyAdded value: +{
+ "description": "Return Core Web Vitals metrics only",
+ "type": "boolean"
+}Input schema / properties / strategy / descriptionPrevious value: -"Device strategy (default: mobile)"New value: +"Device strategy"v1.14.2Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description must disclose behavioral traits, but it only says 'Run ... analysis' without mentioning any side effects, data returned, rate limits, authentication, or caveats. There is zero behavioral transparency beyond the bare action.
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?
The description is a single, front-loaded sentence with no unnecessary words or repetition. It is perfectly concise and structured for quick parsing.
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?
With no output schema and no annotations, the description should explain what the analysis returns and any relevant context, but it does not. It also lacks usage guidance, leaving important context incomplete for a tool with multiple parameters.
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 schema already documents all four parameters. The description adds no extra meaning beyond the schema, earning the baseline score of 3 for high schema coverage.
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 a specific action (Run) on a specific resource (PageSpeed Insights & Core Web Vitals performance analysis) for a page. It effectively distinguishes this tool from siblings like seo_audit or site_health_check by focusing on PageSpeed and Core Web Vitals.
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 provides no guidance on when to use this tool versus alternatives. There are no exclusions, prerequisites, or alternative tool suggestions, leaving the agent to infer usage solely from the tool's name and purpose.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.