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

Annotations already declare a non-readonly, non-destructive write, and the description adds context annotations cannot convey: the two returned links and their purpose, that no order or payment occurs here, and a 30-day retention/deletion policy. It stops short of explaining what happens on a repeated call (relevant given idempotentHint=false) and does not mention auth or rate considerations.

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, front-loaded with the action and its returns, then the scope caveat, then retention. Dense and largely waste-free; the price-block sentence is slightly incidental but still informative.

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 18-parameter mutation tool with an output schema and full annotation coverage, the description supplies the non-obvious pieces an agent needs: it is a save operation, it produces links rather than an order, and the artifact expires. Return-value detail is rightly left to the output schema; auth/permission requirements are the only notable omission.

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 100%, so every one of the 18 parameters, including the enums and nested LED objects, is already documented in the schema. The description adds no parameter-level meaning beyond what the schema provides, so the baseline of 3 applies.

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+resource (saves the priced mirror as a design) and its concrete output (configurator link + checkout link). It also explicitly anchors itself against a sibling by noting it returns "the same price block as quote_mirror," so an agent can separate it from the quote tool without reading either schema.

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 implied rather than stated: the object being saved is "the priced mirror," which implies quote_mirror runs first, and "nothing is ordered by this tool" implies ordering happens elsewhere. There is no explicit when-to-use/when-not statement or named alternative for the pricing-versus-saving decision, so this stays at the implied-usage level.

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