lighthouse_audit

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

Annotations already mark readOnlyHint=true, and the description adds value by disclosing runtime (15-30 seconds), the underlying engine (real Google Lighthouse), and core metrics (scores, Core Web Vitals, top opportunities). No contradiction with annotations.

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 concise (3-4 sentences) and front-loaded with the core purpose. Every sentence adds useful information without redundancy.

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?

Given the presence of an output schema, the description appropriately summarizes return values (scores, vitals, opportunities) without excessive detail. It covers key behavioral aspects (time cost) and is complete for a read-only audit tool.

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 is 100%, with both parameters (url, strategy) described in the schema. The description does not add additional semantics beyond what the schema already provides, so baseline 3 is appropriate.

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 runs Google Lighthouse via PageSpeed Insights API and returns performance, accessibility, SEO, and best-practices scores. It is specific about the resource (URL) and the verb (run/audit), but does not explicitly distinguish from sibling tools like accessibility_audit or performance_audit.

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 implies usage for comprehensive web page auditing, but does not provide guidance on when to use this tool versus more focused siblings (e.g., seo_audit, security_audit). No when-not-to-use or alternative conditions are mentioned.

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