pagespeed

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

No annotations present, but the description covers key behavioral aspects: read-only operation, rate limits, and that results include lab and field data. Transparent about return data structure.

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?

Extremely concise: one sentence detailing outputs, one sentence on quotas. No fluff, front-loaded with purpose.

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?

No output schema, but the description enumerates key return values: performance score, lab CrUX, field data, opportunities. Adequately complete for a simple API 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 descriptions for both parameters. The description adds no extra semantic meaning beyond restating defaults and one usage note. Baseline score of 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?

Clearly states it runs PageSpeed Insights and lists specific outputs (score, Core Web Vitals, field data, opportunities). Does not explicitly differentiate from siblings like 'audit_page' but the focus on performance makes it distinct.

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?

Mentions keyless usage with rate limits and optional API key for higher quota, providing usage context. Does not explain when to use this tool versus similar siblings.

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