traffic

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds useful behavior: aggregation by source/medium, separate AI-referral totals, per-assistant landing pages ordered 'most sessions first', and the GA4-only constraint. It says nothing about date window handling, compare behavior, or truncation via limit.

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?

Three tight sentences, front-loaded with the primary output and followed by the AI-referral nuance and the eligibility caveat. No filler, though the landing-page ordering detail could be trimmed.

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, 6 undocumented parameters, and a compare flag, the description is too thin to call the tool correctly. Return shape is sketched but the request-side semantics, the most important gap, are entirely absent.

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% across 6 parameters, so the description carries the full burden and fails it: site is only implied, and days/start/end/limit/compare are never mentioned. An agent cannot learn the default 28-day window or what limit and compare do from this text.

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 concrete verb+resource: GA4 sessions broken out by source/medium, plus AI assistant referral totals with landing pages per assistant. That is specific enough to separate it from search_queries/bing_queries/page_queries, though it never names a sibling to contrast with.

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 only guidance is the eligibility gate 'Only for sites with GA4.' There is no statement of when to pick this over the query tools, no mention of date-range expectations, and no exclusions beyond the GA4 prerequisite.

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