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

readOnlyHint=true already covers the safety profile, and the description goes beyond it by describing the returned shape (per-event aggregation plus the 20 most recent events), which matters because no output schema exists. Auth needs and rate limits are not mentioned, and the '20 most recent' cap is the only disclosed 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?

The payload description is front-loaded in a single dense sentence, followed by a short scope clause. The parenthetical about Hooky.track is somewhat heavy but earns its place by explaining the data source; there is no filler or repetition.

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 a read-only reporting tool with no output schema, the description supplies the important missing piece: what the response contains. Remaining gaps are minor – ordering of events, pagination limits, and the exact default date window (30 days lives in the schema, not the description).

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 all five parameters are already documented, giving a baseline of 3. The description adds one real semantic point – that omitting site_id returns all sites – but says nothing about how days interacts with from/to or how time_zone shifts the daily series.

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 precisely (event stats) and enumerates the payload: per-event count, total value, daily series, and the 20 most recent events. It does not name or contrast with any sibling, but the sibling list (sites, channels, conversations, agents) is far enough away that confusion is unlikely.

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?

Usage is implied by explaining where the data originates (Hooky.track on site or sent from a server), which tells an agent when numbers will exist. There is no explicit when-to-use/when-not guidance and no mention of alternates for time-series or per-site breakdowns.

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