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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds genuinely useful behavioral context beyond that: the authentication requirement (Partner Billing Key) and the underlying endpoint GET /orderbilling. It does not discuss rate limits or failure modes, so not 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?

Three tight sentences: purpose and returned fields first, then the id caveat, then auth and endpoint. Every sentence carries distinct, decision-relevant information with no repetition of the schema.

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 available, the description compensates by enumerating the billing breakdown contents (per-item product cost, shipping, surcharge, tax, fees, discount, total). Combined with the auth requirement and id sourcing, an agent has everything needed to call this correctly.

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 100%, so the baseline is 3; the description nonetheless adds real meaning by disambiguating order_id as the numeric Gooten order id from gooten_get_order rather than the Safe Order ID. It does not mention the optional currency_code parameter, leaving that entirely to the schema, which keeps it from a 5.

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 (billing breakdown of an order) and enumerates the exact fields returned, so it is clearly distinguishable from the sibling gooten_get_order which returns the order itself. The explicit note that it takes the numeric Gooten order id rather than the Safe Order ID resolves the main ambiguity an agent would face.

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?

It tells the agent to source the id from gooten_get_order and warns against the Safe Order ID, which is actionable routing guidance. It also flags the Partner Billing Key prerequisite. It stops short of naming explicit when-not-to-use conditions or pointing to a billing alternative, so it is strong context rather than full usage policy.

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