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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is covered. The description adds one genuinely new behavioral fact — the search is 'Free' — but says nothing about result limits, pagination, rate limits, or result ordering.

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 that leads with cost and scope, then enumerates coverage. The trailing category list is long but each item adds retrieval value; no filler sentences.

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 values need no explanation, and annotations cover safety. However, with four undocumented parameters and no usage routing, the definition leaves real gaps an agent must guess at before calling it.

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% across 4 parameters, so the description must carry the burden. 'Exact model-number items' hints at part_number-style lookup, but it does not explain the query vs part_number distinction, the anyOf requirement, what manufacturer does, or what limit controls.

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 ('search') and resource ('PARTS INTELLIGENCE catalog') and enumerates the item categories covered, including discontinued and replacement parts. It is clear what the tool does, though it never names or contrasts itself with siblings like parts_intelligence, parts_status, or commerce_search.

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?

Usage is only implied by the catalog description; there is no explicit when-to-use, when-not-to-use, or alternative-tool routing among the many sibling search/intelligence tools. An agent must infer on its own when this beats commerce_search or full_intelligence.

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