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

Annotations already declare this a read-only, idempotent, non-destructive, open-world operation, so the safety profile is covered. The description adds the analytical intent (surfacing units to remove/resize/move) but says nothing about required date-range behavior, defaults, pagination, or result grouping that a performance report would need.

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 short, front-loaded fragments with zero filler — the metric list comes first and the action-oriented purpose second. It is efficient, though arguably undersized for a four-parameter reporting tool.

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 four parameters, only 25% schema coverage, and no output schema, the description should carry more weight. It omits time-range semantics, result ordering/aggregation, and the limit cap, leaving real gaps for an agent trying to call it correctly.

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 only 25% — only 'property' is documented, while startDate, endDate, and limit are bare. The description does not compensate at all, never mentioning the date range, the limit/pagination cap, or how the property id is obtained.

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 (ad units) and enumerates the exact metrics returned (earnings, impressions, RPM, CTR, viewability), so an agent knows what data this yields. However, it never distinguishes itself from close siblings such as adsense_ad_units, adsense_report, or adsense_top_pages, which an agent would need to choose between.

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?

"Identifies units to remove, resize or move" implies an optimization/diagnostic use case, which is genuine guidance. But there is no explicit when-to-use condition, no prerequisite (e.g., requires an AdSense account id and a date range), and no named alternative to prefer instead for simple ad unit listing.

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