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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered. The description adds genuinely useful behavioral context beyond that: it enumerates what is returned and explicitly states a negative constraint ('Coupon codes themselves are not returned'), which prevents a wrong assumption about the output.

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?

Purpose and scope are front-loaded in the first sentence, with the important 'coupon codes not returned' caveat and the market note following. The middle clause is a long run-on enumeration, but every sentence carries information and nothing is wasted.

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?

An output schema exists, so return structure need not be explained, yet the description still summarizes the payload and the key exclusion. Combined with annotations covering the safety profile and a required-single-param schema, an agent has everything needed to call it correctly.

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 the schema already documents both domain and market with its us/ca values. The description adds a concrete domain example (target.com) and restates the market=ca behavior, but adds little semantic depth beyond the schema. Baseline 3 is appropriate.

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 ('Get'), the exact resource (a store's RetailMeNot coupons and offers), the input mode (by domain, e.g. target.com), and enumerates the payload: store details, rating, category, offer counts, coupons/sales/cash-back/in-store offers, similar stores, FAQs. This clearly distinguishes it from the sibling retailmenot_stores list tool.

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?

Implies usage (look up one store's offers via its domain) and gives a concrete market-switch instruction for Canada, but never explicitly routes the agent against alternatives like retailmenot_stores, retailmenot_category, or retailmenot_cashback. Adequate but no when-not guidance.

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