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

No annotations are provided, so the description carries the burden of behavioral disclosure. It accurately conveys the tool's main function (returning scores) but omits details such as whether the tool relies on Google's API, potential rate limits, error behavior for invalid URLs, or whether it returns a single score per category or a full report. This is a moderate gap for a simple read-only tool.

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, concise sentence that packs essential information without fluff. Every word contributes meaning by naming the service and the categories of scores. It is front-loaded and easy to parse.

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 only two simple parameters and no output schema, the description covers the core functionality. However, it does not clarify whether the URL is required (schema lists no required fields), nor does it explain the difference between this tool and a more comprehensive seo_audit. This ambiguity could lead to mis-selection, so the description is not fully complete.

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?

The input schema covers both parameters (url and strategy) with clear descriptions, so the description does not need to add much. The description adds no extra parameter context beyond the schema, which is acceptable given the 100% schema coverage. The baseline of 3 applies.

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 identifies the tool as providing Google PageSpeed Insights scores for Performance, SEO, Accessibility, and Core Web Vitals. It uses a specific resource (PageSpeed Insights) and outcome (scores), which distinguishes it from broader SEO tools like seo_audit or health_check. However, it lacks an imperative verb like 'get' or 'run', making it slightly less explicit than ideal.

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: when you need PageSpeed scores, use this tool. It does not explicitly state when to use it over siblings such as seo_audit or health_check, nor does it mention exclusions or alternatives. Since the purpose is fairly self-evident, the usage guidance is adequate but not explicit.

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