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

Annotations already declare read-only, closed-world, non-destructive, so the safety profile is covered. The description adds the default lookback window and notes about AI Search and shipped_work dimensions, but says nothing about result volume, the 500-item cap, or whether reports are paginated — meaningful gaps for a 14-report 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?

One tight paragraph: the capability first, the report list second, then defaults. No preamble or repetition of the schema, and the trailing notes are short.

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 9 parameters, no output schema, and only partial schema descriptions, the description should clarify filter behavior and per-report parameter applicability. It covers defaults and a couple of domain quirks but leaves an agent guessing about how to shape filters and dates for specific reports.

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 56%, and the description fills one hole by stating the default period, which informs from/to. But it adds nothing about filters, siteId, limit, or which parameters are only valid for certain reports (metric/interval scoping lives in the schema, not the prose). Baseline 3 fits.

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?

Specific verb and resource ("Run any report on the site's traffic") with the full report vocabulary enumerated, so an agent knows exactly what it retrieves. It doesn't explicitly contrast with neighbors like visibility or search_positions, but the traffic-report scope is clear enough to separate them in practice.

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?

Gives a useful default ("last 28 days") and implies this is the go-to traffic query, but never states when to pick this over siblings (visibility, search_positions, funnel_check) or when-not to use it. Selection is left to inference from the report enum.

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