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

Annotations already cover the safety profile (read-only, idempotent, non-destructive, closed-world), so the bar is lower, and the description still adds meaningful context: the returned figures are an estimate, the binding price appears at checkout on lustrix.eu, delivery prices come from a rate table, and a delivery window/orderability flag is included. It does not discuss failure modes for invalid combinations (e.g. height2Cm only for trapezoids).

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?

Three sentences, front-loaded with the core action and its output, followed by the estimate caveat and the caller rule. No filler, though the enumeration of returned fields is somewhat list-like and could be trimmed against the output schema.

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?

With 16 parameters at full schema coverage and an output schema present, the description need not restate parameters or return shape; it correctly focuses on scope, the estimate caveat, and the paid-option rule. It is complete enough to invoke correctly, with only minor gaps around sequencing with the list_* siblings.

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 the baseline is 3 and the schema already carries per-parameter meaning. The description adds only the paid-options inclusion rule (which the schema itself repeats with 'paid; only when asked') and the postalCode estimate note, so it adds little beyond the structured fields.

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 ('Prices one mirror exactly as the shop does') and enumerates what the quote contains, so an agent knows precisely what action is performed. It does not name or differentiate itself from the siblings create_design_link, list_materials or list_options, which is the only thing keeping it from a 5.

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?

There is real guidance embedded: 'Only include paid options the customer asked for' and 'add postalCode for a delivery estimate'. However, there is no statement of when to use this tool versus the sibling lookup tools, nor any preconditions (e.g. that materialSlug and shape must first come from list_materials/list_options). Usage is implied rather than spelled out.

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