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

With no annotations at all, the description carries the full burden; it does disclose the catalog's size and domain coverage, the two required inputs, and the returned fields. It omits pagination/total-count behavior despite exposing limit and offset, says nothing about empty-result behavior, and never explicitly states the operation is a read-only lookup. Adequate but with real gaps for an annotation-free tool.

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: purpose first, return shape second, intended use and prerequisites last. The parenthetical category list is the only slightly expendable element, but it conveys catalog breadth efficiently.

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 7-parameter search tool with no output schema, the description does tell the agent what comes back (asin + buyUrl) and what is mandatory. It leaves pagination behavior, result ordering, and total-count semantics unexplained, which matters given limit/offset are present.

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 71%, below the threshold where the schema alone would suffice, so the description should compensate more. It does reinforce that marketplace and locale are required, but q, limit, offset, ageBand, and interest are only documented in the schema — the description adds no filtering or pagination semantics of its own.

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 names a concrete verb and resource — searching a curated baby registry catalog with a stated scope (100+ amazon.se essentials across eight categories) — and states the return shape (asin + buyUrl). It does not name the sibling tools search_suggest or resolve_product, so the agent must infer the boundary between catalog search and product resolution.

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?

"Use to pick items when building a shopping list / registry" gives a clear triggering context, and "Requires marketplace + locale" flags the two mandatory inputs. There is no explicit when-not guidance or routing to siblings (e.g. resolve_product for a specific known item, search_suggest for query autocomplete), which keeps it below a 5.

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