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

With no annotations, the description does useful work by disclosing the exact surcharge model (+R5 per AI-styled magnet, +R50 gift wrap, courier delivery) and the market (South Africa, i.e. ZAR). It does not state that the operation is a side-effect-free calculation, does not explain how courier cost is derived or rounded, and says nothing about whether the quote is persisted or has a validity window.

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?

A single front-loaded sentence with no filler; every clause (item costs, AI surcharge, gift wrap, courier) maps to a real component. It is dense but not bloated.

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 4-parameter, zero-annotation, no-output-schema tool, the description covers the pricing inputs well but omits what the response contains (a single total vs. a line-item breakdown), how delivery cost is determined, and any quantity constraints. Complete enough to invoke, not complete enough to predict the result.

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% and the schema already carries the R30/R270/R5/R50 pricing semantics, so the description largely repeats it. The one added insight is that courier delivery is a computed component rather than a parameter, which is minor at a 3 baseline.

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 pairs a specific verb ('Calculate') with a specific resource ('instant order quote for MagSnap photo magnets') and enumerates the pricing components, so an agent can tell it is a pricing engine rather than a purchase tool. It never names or contrasts with the siblings (create_checkout_link, get_products), so it falls just short of 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 no explicit statement of when to call this versus create_checkout_link or get_products, and no prerequisites or exclusions are given. Usage is only inferred from the word 'quote', which is too thin for a tool whose siblings include an actual checkout action.

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