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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so the safety profile is covered. The description adds the 'right now' freshness semantics and the returned price/full-price/discount fields, which is genuine extra context, but it says nothing about ranking determinism or result counts.

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?

A single front-loaded sentence with no filler; the core resource is stated before the qualifying clauses. Slightly dense with parentheticals but every clause carries information.

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 usefully names the return fields, and the required domains parameter is covered by the schema. However it omits the limit default/cap behavior and gives no guidance on combining multiple domains across accounts, leaving gaps for a read tool with three parameters.

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 67% and the enum for sort is already documented ('Default percent'). The description's 'by % or amount ... or its newest discounts' maps loosely onto those enum values without adding syntax or defaults beyond the schema, and the limit parameter is undocumented in both places. Baseline 3.

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+resource ('a brand's most-discounted products right now') and enumerates the returned fields (price, full price, discount), which separates it from analytics siblings like get_discount_frequency_and_depth. It does not explicitly name which sibling to use alternatively, so it stops short of full differentiation.

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?

The phrase '(by % or amount) or its newest discounts' hints at the sort modes but never says when to pick this over get_active_promotions_and_coupons or get_discount_frequency_and_depth. No prerequisites, no exclusions, no explicit alternative routing.

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