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

With no annotations, the description carries the whole burden and does substantial work: prices exclude VAT (added at payment by location), non-GBP is a live-rate conversion of a GBP base, domains are priced separately and annually, and licence plans have forced-annual semantics. It omits auth requirements, error behaviour, and rate limits, but the pricing caveats are exactly the non-obvious traits an agent needs.

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?

Front-loads the core purpose in the first clause, then layers the caveats (VAT, currency, licence plan) in descending order of importance. Dense but every sentence carries pricing semantics that would otherwise be unguessable; slightly more length than strictly necessary.

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?

No output schema and no annotations, so the description must define both call semantics and result meaning – and it does state the result is an estimate matching the site and cart. For a 6-parameter pricing tool with 0% schema coverage, the gaps are the return shape and failure modes, which are secondary.

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 0%, so the description must compensate and largely does: it explains domain (priced separately, annual), currency (non-GBP live conversion of GBP base), billingCycle (driven by plan/licence rules), configSelections (omitted = defaults), and add-ons. Only packageKey is left implicit, and no key-format syntax is given.

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 ('Price') and resource ('a configured UmbHost order') and pins the exact semantics: it mirrors the website's pricing calculator output. An agent can distinguish this from get_plan (retrieval) and begin_checkout (transaction) without opening any 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?

Gives concrete operating guidance: omit configSelections to take plan defaults, and the special licence-plan case where cycle is forced Annual and domains cannot be added. It does not explicitly name when to prefer this over siblings like get_plan or begin_checkout, so it falls short of a full routing statement.

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