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

Beyond readOnlyHint, it discloses that results are exhaustive with no sampling and that incomplete or stale data fail loudly rather than yielding false uncovered results. It also states required backend preconditions, though it does not discuss pagination or response shape.

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 purpose and safety/scope constraints are front-loaded in a compact paragraph. Some repetition of READ-ONLY is redundant with annotations, but overall it is appropriately sized for a complex coverage check.

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 six-parameter read-only tool with no output schema, it describes the returned fields, cross-referencing behavior, error semantics, and prerequisites. The main remaining gaps are full parameter semantics and response structure, but it is largely complete for correct invocation.

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 50%, and the description adds meaning mainly for the only_with_sales/only_uncovered combination. It leaves lookback_days and only_in_stock without added semantic detail, while account_id and ignore_orphan_ads rely on their schema descriptions.

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 opening states the exact resource and scope: all catalog ASINs plus recent outpost sales, one row per ASIN, including SKU, title, stock, sales, and live Sponsored Products coverage. It also says it cross-references Product Ads and campaign/group states, which distinguishes it from generic catalog or ads-listing siblings.

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 a concrete filter recipe for the 'sold without active SP' case (only_with_sales=true and only_uncovered=true) and states prerequisites such as a synced data-hub and linked Ads. However, it does not name alternative tools or explicit when-not conditions, so sibling routing remains implicit.

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