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

Annotations already declare the safe read-only, idempotent profile, so the description is free to add context: the response includes timeline annotations that fall inside the window, and supplying event_name changes the returned series to that event plus conversions. That is genuine output-shape information beyond the structured fields, though default interval and timezone behavior are left to the schema.

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 short sentences, front-loaded with what is returned, followed by use case and then the alternate mode. No filler or restatement of the name.

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?

For an 8-parameter read tool with no output schema, the description covers purpose, bucket granularity, window semantics implicitly, and the event_name variant. Filters and timezone handling are only in the schema, but since their descriptions are complete, nothing critical is missing.

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%, so every parameter already carries its own description; the description only echoes interval choices and the existence of event_name. Its one real addition is that event_name returns conversions per bucket rather than plain visits, which the schema does not say. Baseline 3 applies since the schema does the heavy lifting.

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 specific resource and metric (visits and pageviews) plus the bucket granularity (hour/day/week) over a window, which is enough to distinguish it from aggregate tools like get_overview. It never names a sibling, so the boundary versus get_breakdown or get_heatmap must be inferred.

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?

"Use it to find when something changed" gives a clear investigative use case, and the event_name clause explains the alternate mode of operation. There is no explicit when-not guidance or named alternative for drill-down vs. breakdown queries.

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