page_stats

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

No annotations are provided, so the description must carry the behavioral disclosure burden. It reveals that the tool reports element count, size, and load metrics, which implies a read-only diagnostic operation, but it does not explicitly state that no navigation or state mutation occurs, nor does it describe how the metrics are collected. This is adequate but not rich.

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 no filler. The core information 'element count, size, load metrics' is front-loaded, and the use case follows immediately. Every part contributes value.

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 no output schema and no annotations, the description is the main contract for the agent. It names the metric categories but leaves 'size' and 'load metrics' underspecified, and does not state whether the stats apply to the current page or require a completed page load. This is minimally sufficient for a 0-param tool, but it leaves gaps.

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 tool has zero parameters, so there is no semantic ambiguity for an agent to resolve. The rubric baseline of 4 for 0-param tools applies; the description does not need to add parameter detail.

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's function: reporting page-level statistics such as element count, size, and load metrics. It is not a tautology and gives enough specificity to separate it from content-gathering tools like get_text or screenshot, though it does not explicitly differentiate it from similar diagnostic siblings like performance_timeline.

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 explicitly states a use case: 'Use to decide extraction strategy.' This gives an agent a clear context for when to invoke it. It does not mention exclusions or alternatives, so it falls short of the highest benchmark.

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