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

Annotations already mark this as read-only and open-world. The description adds useful behavioral context beyond that: it returns live price, stock, and product URL, and it stresses that different sizes are not exact substitutes. It does not discuss pagination or error behavior, but the annotation coverage lowers the burden.

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?

Four sentences, each earning its place: what it searches, the exact-match constraint, the return payload, and the sibling alternative. The most important guidance is front-loaded, and there is no filler.

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 simple read-only search with two parameters and no output schema, the description covers query semantics, match strictness, return fields, and the relevant alternative. The only notable gap is the unresolved mismatch between the description's SKU/dimension search claim and the schema's narrower query field description.

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?

The description adds meaning to the query parameter by saying it can search by category, SKU, or exact dimensions, and that dimension matches must be exact. However, this goes beyond the schema's query description ('matches title, vendor, type, tags'), creating a mild inconsistency. The limit parameter is self-explanatory from its schema constraints.

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 opens with a specific verb and resource: 'Search Packrift by category, SKU, or the exact dimensions...' It clearly distinguishes the tool from find_packaging_for_item by naming that sibling directly and stating the different use case. An agent can tell exactly what this tool does.

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?

It provides an explicit routing rule: when the buyer describes an item's dimensions and needs packaging that fits around it, use find_packaging_for_item instead. It also warns that exact dimension tuples and pack counts must match, preventing approximate-match queries.

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