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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description is consistent with that (a non-mutating check). It adds real behavioral context beyond the annotations: the four outcome states, the not_connected failure mode, and the required agent action on it. It does not cover batching limits or rate behavior.

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?

Three short sentences, front-loaded with the core purpose, followed by the input instruction and the error branch. No filler or redundant restatement of the tool name.

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 does the right thing by enumerating the result values and the not_connected case, and it names the skill that consumes it. The only minor gap is that conditionType's effect on results is left entirely to the schema.

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 100%, so both parameters (asins with 1-200 bounds, conditionType with its default) are already documented in the schema. The description only restates 'pass the ASINs' and adds no extra meaning, so the baseline of 3 applies.

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 verb (check), resource (listing eligibility of ASINs) and scope restriction ('YOUR connected Amazon seller account'), and enumerates the possible outcome states (ELIGIBLE / GATED / RESTRICTED / UNKNOWN). An agent can distinguish this from siblings like get_amazon_asin_price_history or search_retailer_products without opening any 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?

Tells the agent to pass the ASINs to verify and gives an explicit branch on the not_connected result ('tell the user to connect their Amazon seller account and stop'), plus notes it belongs to the Verify Leads skill. No alternative tool is named for overlapping cases, so it stops short of a 5.

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