pagespeed

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, so safety is covered. The description adds useful cost context ('Free tier') and hints at scoped output ('selected audits'), but does not describe rate limits, authentication, or which audits are actually returned.

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 two short sentences with the purpose front-loaded and little wasted text. The phrase 'selected audits' is vague, but overall it is appropriately sized for a simple tool.

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?

For a read-only tool with rich annotations, the safety profile is already handled. But with no output schema and zero parameter description coverage, the description omits what 'selected audits' means and how strategy affects results, leaving meaningful gaps for an agent trying to call it 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?

With two parameters and 0% schema description coverage, the description should explain the required url and the optional strategy/default mobile behavior. It mentions neither, leaving the strategy enum entirely undocumented in prose.

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 states the resource (PageSpeed Lighthouse score) and a return element (selected audits), which is clear enough to identify the tool. However, it lacks an explicit operation verb and does not distinguish itself from siblings like crux, which also deals with performance data.

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 such as crux or gsc_inspect. 'Free tier' gives licensing context but does not help an agent decide when this tool is appropriate.

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