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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description contributes nothing further: no word on how far back LIFETIME reaches, whether data is real-time or lagged, or how pagination interacts with the date scope.

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?

One short fragment with no padding. It is appropriately sized in the literal sense, but the brevity reflects under-specification rather than disciplined editing, so it lands at the minimum-viable mark.

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 four fully documented parameters, no nested objects, and a clear read-only annotation profile, the structured fields cover most of what an agent needs. The missing piece is disambiguation from the many sibling stats tools, which the description leaves entirely to the reader.

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%: pagination, sorting, and the dateRange enum are fully documented inline with defaults and examples. The description adds no parameter meaning beyond the schema, which is the expected baseline of 3 when the schema does the work.

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 names the resource ('website visitor engagement metrics') and lists the metric families (session data, page views, visitor behavior), so the domain is clear. However, it is a noun phrase with no verb, and it does not distinguish itself from overlapping siblings such as performance_metrics, account_level_stats, or deep_funnel_stats.

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 guidance on when to call this tool versus performance_metrics, account_level_stats, or demographic_country_stats. An agent must infer from the name alone that this is a website-side report rather than a campaign-side one.

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