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

With readOnlyHint=true the safety profile is already covered by annotations, so the description only needs to add context. It contributes the field inventory and the units of monetary fields ("retail and wholesale cost in cents") along with the underlying endpoint POST /v3/inventory_part/search, which is useful. It says nothing about result volume, pagination behavior, or default result set size.

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?

One front-loaded sentence stating the resource and its fields, followed by a filter example and the endpoint reference. Every element is relevant, though the field enumeration is a long run-on list that could have been trimmed given the schema carries the parameter details.

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 an optional-parameter search tool with no output schema and read-only annotations, the description covers what is searchable, the filter shape, and the backing endpoint. It does not describe the response envelope or pagination semantics indirectly, but the schema's skip/limit descriptions largely fill that gap.

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. The description supplies a filter example ({"sku": "ABC-123"}) that illustrates the intent of the `where` object, but it never maps that example to a named parameter and does not explain `skip`, `limit`, or `orderBy`, which the schema already documents.

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 states a specific verb and resource ("Search the parts inventory") and enumerates the searchable/returnable fields (SKU, part number, bin location, costs). That is enough for an agent to know exactly which API operation this is. There is no competing inventory sibling in the tool list, so sibling differentiation is trivially satisfied rather than explicitly demonstrated.

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 description shows a filter example ({"sku": "ABC-123"}) but never says when to use this tool versus the many customer/order/appointment siblings, nor when it would be the wrong choice. There is no mention of prerequisites, required identifiers, or scope limits such as whether it searches all inventory or a single location.

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