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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=false, so safety is covered; the description adds substantive content beyond that by spelling out what the response contains (per-field item counts, custom vs. shopping attribute classification, before/after coverage). It stops short of noting result size, pagination, or cost of the call, which keeps it from a 5.

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 is front-loaded with the core definition before the sibling routing, and nearly every clause adds information an agent needs. It is dense and runs long for a one-parameter read tool, with the triad framing consuming part of the space, but there is little outright filler.

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 carries the burden of describing return values and does so concretely: per-field value counts, attribute classification, empty-row detection, and before/after coverage. What is missing is anything about result size, ordering, or whether coverage numbers are per-feed or per-attribute aggregate in practice.

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% and the single parameter feedId is documented there ('Feed id from list_feeds'), so the baseline is 3. The description adds no additional meaning about feedId, such as whether the inventory is scoped to the latest run or a snapshot, so it does not exceed the baseline.

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?

States a specific resource (the merchant's source feed field inventory) and exactly what it reports: per-field presence, recognition status, empty-on-every-row detection, and coverage before/after the rule stack. It explicitly positions itself against siblings get_audit_findings and get_merchant_issues, so an agent can distinguish it without opening the schema.

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?

Gives an explicit ordering instruction ('Use it BEFORE proposing rules') and names the two alternative diagnosis tools with the axis that separates them (merchant sent vs. SKULayer thinks vs. Google thinks). It also states the distinguishing question only this tool can answer: never-sent vs. sent-blank vs. unusable-value.

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