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

No annotations exist, so the description carries the full burden and does well: it names both data sources (AusPost retail PAC and Easyship's commercial panel), the return contents (price, currency, transit time), sorting (cheapest first), and a caveat that the two sources are not directly comparable. Auth, rate limits, and error behavior remain undisclosed, keeping it from a 5.

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 capability before the usage sentence, and each sentence contributes (sources, return shape, sorting caveat, when to use). Slightly dense but no wasted filler.

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, the description usefully explains the return structure and a comparability caveat; with no annotations, it discloses the dual-source behavior. Parameters are fully covered by the schema. Mostly complete, though mutation/auth/rate-limit context is absent (not applicable to a read-only quote, so minor).

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 the schema already documents all 8 parameters (defaults, ranges, enums, examples). The description only alludes to 'weight and route'; it adds no syntax or format detail beyond the structured fields, making the baseline 3 appropriate.

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+resource (live shipping prices for a domestic Australian parcel) and adds distinguishing scope: 'WITHIN Australia', 'two independent sources at once'. This clearly separates it from the sibling quote_international_from_au without opening the 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?

Provides explicit when-to-use: 'asked what it costs to send a parcel between Australian postcodes, or which courier is cheapest for a given weight and route.' It does not name alternatives or state exclusions (e.g., when to reach for quote_international_from_au), so it stops short of a 5.

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