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

The annotations already establish read-only/non-destructive behavior, and the description adds substantial value: it identifies which numbers are safe to quote for ad spend/ACoS, warns that SB per-ASIN spend appears only in the blended PnL, and explicitly says campaign-grain data must never be summed as a product total. These are critical behavioral caveats beyond the annotations.

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 description is dense but every clause earns its place: it front-loads the canonical status, lists all included views, and embeds necessary warnings inline. It avoids filler and relies on structured labels and caveats rather than redundant prose.

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?

Given there is no output schema, the description does a good job enumerating the returned views and critical caveats. It is less complete on input semantics and response structure, but for a read-only aggregate report the core selection and interpretation guidance is present.

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 14%, so the description needs to compensate, but it never explains sku, asin, end_date, or parent_sku. It gives contextual hints around 'product/family' and 'family resolution,' but not enough for an agent to know how to populate or scope the parameters correctly.

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 a specific resource ('canonical product/family report') and a specific action ('ONE call returning every view labeled...'). It enumerates the constituent views and explicitly frames itself as the preferred option for product performance questions, clearly distinguishing it from sibling tools that return individual pieces.

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?

It gives an explicit usage directive: 'PREFER this over assembling the pieces yourself for any "how is product X doing" question.' It does not name specific alternative tools or describe when to avoid this tool, but the usage context is clear enough for an agent to route correctly.

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