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

With no annotations, the description carries the full behavioral burden and does so well: it discloses that prices EXCLUDE VAT (added at payment by location), that non-GBP is a live-rate conversion of a GBP base, that the domain is priced separately and annually, and that the result matches the site and cart. It stops short of auth requirements, error modes, or rate limits.

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 purpose, then behavioral caveats. Dense but nearly every clause earns its place by disclosing pricing semantics; only mild redundancy between 'matches the site' and 'the way the pricing calculator does'.

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 tool with no output schema and no annotations, the description compensates well by explaining what the estimate represents (matches site and cart, excludes VAT, currency conversion). The main gap is that required parameter semantics (packageKey, valid currency/cycle strings) are not covered.

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% at the top level, so the description must compensate. It adds real meaning for currency (live-rate conversion), billingCycle, domain (annual, separate line), and configSelections (omit for defaults), and addons are named. However, the required packageKey is never explained and accepted values/formats for currency and billingCycle are absent.

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 and resource: it prices a configured hosting order the way the website's pricing calculator does, enumerating base plan + config options + add-ons. This is far more specific than a tautology, but it never names or contrasts with siblings like get_plan, list_plans, or begin_checkout, so the differentiation is left to inference.

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 when-to-use, when-not-to-use, or alternative routing. The only guidance is an operational note ('Omit configSelections to use the plan's defaults'), which is parameter behavior, not usage scope. An agent must guess how this relates to get_plan or begin_checkout in a workflow.

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