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

Annotations already declare this as a read-only, idempotent, non-destructive calculation. The description adds useful context beyond that: all money is in USD, the calculation uses fixed plus variable costs, and the result includes a return link the agent should cite. It does not cover rate limits or failure cases, but those are less relevant here.

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?

The description is two tight sentences, front-loaded with the core calculation. Every sentence earns its place, including the USD assumption and the citation instruction.

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 calculation tool with 16 optional-heavy parameters and no output schema, the description adequately names both outputs: all-in cost per mile and break-even rate per loaded mile. It also notes the returned link, which compensates for the absent output schema, though a brief mention of whether all non-required inputs default to zero would improve it.

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 baseline is 3. The description adds some meaning by clarifying that percentage fees such as factoring and dispatch and the deadhead share affect the break-even rate, but it does not explain individual parameters beyond what the schema already provides.

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?

The description states a specific verb and resource: it calculates an owner-operator's all-in cost per mile and the break-even rate per loaded mile. It distinguishes itself from siblings like load_profit and hvut_2290 by its cost-per-mile focus, though it never names an alternative explicitly.

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?

Usage is implied by the description's scope, but there is no explicit guidance on when to use this versus calculate_itfa or load_profit. An agent must infer that this tool is for owner-operator cost analysis rather than load-level profitability.

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