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

With no annotations, the description carries the full burden and does a good job: it discloses that results include each discount plus a link to unlock it, and critically that promo codes are NOT returned here and require a signup at the link. This pre-empts the most likely agent failure mode. It stops short of stating result limits, pagination, or whether results are ranked, which leaves some behavioral gaps.

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 tight sentences with zero waste. The searchable scope is front-loaded, the return shape follows, and the promo-code caveat comes last where it belongs. Every sentence adds information the agent needs.

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 single-parameter, no-output-schema search tool, the description covers purpose, query semantics, and return content including the key limitation that codes require signup. The remaining gap is result-set behavior (how many offers, pagination, ranking), which matters somewhat for a search tool but is not disqualifying.

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% so the baseline is 3, and the description earns an extra point by widening the parameter's meaning beyond the schema: the schema says 'Brand name or keyword' while the description explicitly adds 'product type' with concrete examples like 'stroller' and 'diapers'. That tells the agent a generic product noun is a valid query, which the schema alone does not convey.

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 description uses a specific verb and resource ("Search current baby & kids brand discount offers on Cubbie Club") and enumerates the searchable dimensions (brand name, keyword, product type). It does not explicitly distinguish itself from the siblings get_brand_offer and list_brands, so an agent still has to infer that this is the keyword-discovery entry point rather than a direct lookup.

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 usage context is implied by the query examples ('stroller', 'diapers', 'muffins', 'swim'), which show the tool is for broad discovery. However, there is no explicit when-to-use or when-not-to-use guidance, and neither sibling is named as the alternative — nothing tells the agent to prefer list_brands for browsing or get_brand_offer once a brand is known.

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