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

Annotations already establish readOnlyHint and openWorldHint, so the safety profile is covered. The description adds useful behavioral context beyond that: it enumerates the returned product fields, the total count, the facets structure, and the 1-indexed pagination model. It doesn't mention rate limits, auth, or result caps, so not 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?

Front-loaded with scope and the sibling comparison, then params, then sort codes, with no filler sentences. The opening sentence is long and dense, but every clause carries distinct information; slight readability cost only.

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?

Output schema exists, so the description needn't detail return values, yet it still frames the result shape (products, count, facets) helpfully. All three params are covered, the alternative tool is named, and the sort vocabulary is given. Nothing an agent needs to invoke it correctly is missing.

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 0%, so the description carries the full parameter burden and does: q is required keyword/phrase, page is a 1-indexed page number defaulting to 1, and sort is documented with all six enum codes expanded (pa/pd/tr/rc/az/za) plus the relevance default. This is exactly the meaning the schema lacks.

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 and resource ('Search CVS.com's non-prescription retail/OTC catalog by keyword') and immediately names the sibling it parallels (cvs_category) with the differentiating axis: keyword vs category/brand path. An agent can distinguish it from cvs_category and cvs_brands 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?

Explicitly routes between this tool and cvs_category ('the same product-search backend cvs_category reads, just reached by keyword instead of by category/brand path'), which is clear when-to-use guidance. It doesn't cover when-not to use keyword search or prerequisites, so it stops short of full 5.

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