page_speed_audit

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

Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, so safety is covered. The description adds useful context that the call is backed by Google PageSpeed Insights (an external, likely slow, network-bound service) and what results come back, but says nothing about rate limits, timeouts, or failure behavior.

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 purpose sentence is front-loaded and the Args block is terse, with every line carrying information. The trailing '[Provider: Google PageSpeed Insights]' is slightly awkward but still useful metadata rather than filler.

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 two-parameter, no-output-schema tool, the description covers inputs and sketches the return contents (Core Web Vitals, score, opportunities), which is the minimum needed to call it. It omits practical expectations an agent needs for an open-world network audit, notably expected duration, throttling, and error outcomes.

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 0% and 'strategy' has no enum in the schema, so the description carries the burden — and it does: it specifies that url must be a full URL with an example format, and that strategy accepts 'desktop' or 'mobile' with a default of 'desktop'. That adds real meaning beyond the bare string properties.

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?

States a specific verb and resource ('Audit a page's loading performance') and enumerates the payload (Core Web Vitals, performance score, opportunities), which separates it from a general SEO audit. It does not name or differentiate against the sibling on_page_audit, so the distinction is left to inference.

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?

There is no explicit when-to-use or when-not-to-use guidance, no mention of when desktop vs mobile should be chosen, and no note on prerequisites such as API quota or latency. The only implied usage cue is the tool name and the word 'Audit'.

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