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

With no annotations, the description carries the burden and does well: it discloses the two quoting sources, that AusPost pricing is retail-only, that destination duty/tax is excluded and paid by the recipient, and that results come back per service with price and currency. Missing only auth/rate-limit or failure-mode context.

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?

Four sentences, each carrying distinct information: capability, source split, usage trigger, and the pricing caveat. Front-loaded and free of repetition, though slightly dense.

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 9-parameter tool with no annotations and no output schema, the description covers the important gaps: what is returned (per-service price and currency) and the retail/duty caveat. It could say more about which source wins when both quote, but it is largely complete.

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 every parameter (HS code, category enum list, weight cap, postcode roles) is already documented. The description adds no parameter-level detail beyond the schema, so the baseline 3 applies.

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 — live shipping quotes for a parcel sent FROM Australia overseas — and names both price sources (AusPost retail PAC and Easyship commercial panel). This clearly separates it from the domestic sibling quote_domestic_au.

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 an explicit trigger: 'Use when asked what it costs to post something overseas from Australia.' The direction (FROM Australia) implicitly excludes inbound/domestic quoting, but no sibling is named as the alternative for those cases.

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