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

Annotations already declare a safe read-only idempotent call, and the description goes well beyond them: it enumerates return fields, explains at_order_minimum vs the small-part minimum, flags the ~1 minute pricing-busy transient, and explains that available=false carries a licence reason. That is exactly the extra context the annotations cannot supply.

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?

The purpose is front-loaded and the Args block is clean, with no filler sentences. The return-value paragraph is a long run-on clause chain with nested parentheticals, which slightly hurts scanability even though every clause carries information.

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 no output schema present, the description fully describes the response surface (summary, price, at_order_minimum, small_part_price, postage, dispatch time, batch discounts, order_url) plus the unavailable path. For a 3-parameter read tool with rich annotations, nothing material is missing.

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 coverage is 0% and the schema has no enum for material, so the description does the heavy lifting: it lists all 11 accepted material values, gives the quantity range (1-999), and supplies three link-format examples for model_link. Nothing an agent needs to construct a valid call is left to guessing.

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?

Names a specific verb (get price), resource (3D print a catalogue model) and scope (posted in the UK), with the accepted link sources spelled out. It stops short of explicitly contrasting itself with the sibling quote_my_file, leaning on the word 'catalogue' to imply the distinction.

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 by the accepted link formats and the 'catalogue model' framing, and the note about available=false explains a failure case rather than when to pick this tool. There is no explicit when-to-use/when-not guidance against quote_my_file or search_models, so the agent must infer the boundary.

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