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

Annotations already indicate read-only, idempotent, non-destructive. Description adds concrete examples of what it does not do (no carts, checkout, orders, inventory mutations) and preserves FoV provenance, providing additional behavioral context beyond annotations.

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?

Two sentences, each carries essential information. Front-loaded with the core action and constraints. No wasted words.

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?

Lacks parameter details despite moderate complexity. No output schema, but annotations cover behavior. The concept of 'purchase handoff seam' could be clearer, but the description provides sufficient high-level context for selection.

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 has 0% description coverage, and the description does not explain any parameter's meaning or role. It only implicitly references 'selected lens' (sku) but ignores quantity, sensorPartNumber, and selectedVariantId. Fails to add value beyond the raw schema.

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?

Clearly states it builds a read-only purchase handoff seam for a selected lens, with specific exclusions (no carts, orders, writes). Differentiates from sibling tools like create_cart, update_cart, and FoV tools.

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 says when to use: for carrying optical context into purchase handoff. Also provides a firm rule about FoV estimation, directing to specific tools and prohibiting estimation from catalog fields.

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