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 does add genuine domain context beyond that, notably the definition of "credited" and the inclusion of the learning loop's do-more/stop lists. It says nothing about data freshness, sync timing, or whether the last-week figures are provisional, which matter for a performance report.

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?

Two sentences, front-loaded with the per-channel scope and time windows, with the parenthetical metric list carrying real information rather than filler. The closing definition of "credited" is well placed. Slightly dense packing, but nothing is redundant.

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, the description must describe the return shape, and it does: an enumerated metric set, two time horizons, two learning-loop lists, and per-channel link clicks. The main omission is that "the learning loop" and its do-more/stop lists are named but never explained for an agent unfamiliar with the domain.

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?

There is a single parameter and schema description coverage is 100%, so the schema already fully documents productId. The description adds no meaning to that parameter and mentions no scoping or error behavior. Baseline 3 applies where the schema does all 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?

"Per channel: what Hustlin did and what it produced" plus an explicit metric list (attempts, reach, credited signups, purchases, revenue) and two time windows makes the resource and scope unmistakable. It does not, however, differentiate itself from the sibling tools report, report_conversion, or actions, so an agent must infer the boundary.

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 rather than stated: the "last week and over four weeks" framing signals a retrospective performance read, which lets an agent guess when to reach for it. There is no explicit when-not guidance and no named alternative among report, report_conversion, or actions, which is a real gap given how many reporting siblings exist.

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